Hide and Seek
by fireworksinthenight
Summary: When the turtles end up by mistake in their past, they must both avoid their past selves and convince their very protective father and ninja master that they are now able to take care of themselves. Good luck with that.
1. Prologue

_Disclaimer: I do not own the turtles._

 _Set in the 2012 universe. My first fanfic. It just wanted to be written, so I had to comply._

 **Prologue**

The dojo was calm and quiet. A light breeze made the leaves of the beautiful tree move slightly. Master Splinter breathed slowly. He was deep in meditation, enjoying the moment and relaxing after the intense training session he had just had with his four fourteen-years-old sons. His boys were growing up fast and becoming more reckless and he had decided to intensify their training. He had told them it was because they were now strong enough, which was true. He had carefully kept the other reason to himself: if they were exhausted enough, he hoped he could get some peace. At least for a few hours. The tall rat master chuckled silently. So far, it had worked perfectly.

At this precise moment, he heard a small bump and the sound of soft footsteps beside him. Voices echoed.

 _Donnie! What have you done this time?_

 _Nothing, Raph. It looks like the device went wrong. I didn't think we would land in the dojo, just a few meters from my lab, but…_

 _It's okay, bro. You're still the most awesome ninja thing-builder on the planet._

 _Um, guys?_

Master Splinter repressed a sigh. It looked like his precious downtime was coming to an end. He opened his eyes to see four very surprised turtles and frowned. Something was off, and not only because he had expected his sons to be resting in their rooms or watching TV on the couch.

"Ma…master Splinter? What are you doing here?" The turtle who had just spoken wore a blue mask and twin katana.

"Leonardo, my son. What happened to your voice?" The rat master frowned deeper.

"What do you mean, sensei? What is wrong with my voice?" Leonardo answered, surprised.

"Uh, Leo? I think we might have a little problem…" A purple-clad turtle with a bo staff on his back was looking hard at a small device in his hand.

"What else is new," growled another turtle, rolling his eyes behind his red mask and twirling both his sai in exasperation.

"It can't be that bad if we're still in the lair," said an orange-clad turtle happily, two nunchuks at his belt.

At that moment, a new voice spoke from outside the dojo.

"Master Splinter? Who are you talking to?"

This voice had an amazing effect on the four turtles and the rat inside the dojo. They froze in disbelief. Then the blue-clad turtle turned to the purple-clad turtle and whispered between clenched teeth.

"Donnie… Please tell me this is not happening…"

"It is… I have no idea why but it is!"

Master Splinter was finding it hard to process what was happening. He had just heard Leonardo's voice from outside the dojo, but his son was standing right in front of him. His voice had sounded strange when he had spoken instants ago. Maybe this was some kind of joke? Was he learning ventriloquism? It was not something he would have expected of his ever so respectful son, but teenagers were known to be unpredictable. He was about to say something when Leonardo whispered again with this strange voice of his.

"Ninja! Disappear!"

And the rat watched in disbelief as the four turtles disappeared quickly, apparently hiding behind the tree. This was becoming ridiculous. He would have to give them a piece of his mind. Maybe training hadn't been as exhausting as he thought…

"Sensei?" The normal Leonardo voice was heard again, and this time its owner stepped into the dojo. Master Splinter looked at him, speechless. He could have sworn he had just hidden behind the tree. Something was definitely amiss here.

"What is the matter, my son?"

"I…I thought I heard you talking to someone," answered a perplexed turtle, looking at his sensei apparently very alone in their dojo.

"Leonardo. Is there something you want to tell me? Where are your brothers?"

"Mikey is watching TV with Raph and Donnie is in his lab. I am sorry to have disturbed you, sensei. Please forgive me," said Leonardo, finally considering he had just imagined the whole thing. He was still sore from their earlier training. Maybe he was more tired than he had thought?

Master Splinter was confused too. But he kept his voice calm and answered gently.

"You may go."

Leonardo bowed and left the dojo. The rat master waited a few seconds before standing up and going around the tree to contemplate four ninja turtles pressed against the trunk and hanging from the branches, one of them having supposedly just left the room. He looked at them with an intense look in his eyes.

"Does someone care to explain?"


	2. This Is Messed Up

**Chapter 1: This Is Messed Up**

The four turtles were lined up in front of their father, in their master's personal quarters. They had silently followed him here from their not-so-good hiding place behind the dojo's tree. So far, they had exchanged panicked glances but none of them had spoken.

Master Splinter looked carefully at each one of his sons. Raphael was looking at the floor like it was the most interesting thing he had ever seen. Leonardo contemplated his hands carefully resting on his knees, obviously avoiding eye contact with his sensei. Donatello was still looking at his device and frowned the way he used to when he was confronted with a particularly difficult problem. Only Michelangelo was looking directly at his father. More exactly, he was beaming at him. Seeing that familiar smile, the rat master relaxed slightly and asked again.

"What is going on here?"

Leonardo looked up and blinked.

"I am not exactly sure, sensei. You see, we are kind of coming from another place…uh…"

"Not another place, Leo! Another time! This is awesome!" added Michelangelo, still beaming.

"This is absolutely not awesome, Mickey! This is not the way it was supposed to be!" said a desperate Donatello. "How are we going to fix this? We can't alter the past in any way or we could stop existing in our present!"

"Looks already pretty altered to me," muttered Raphael, who was now admiring the wall behind Splinter. A very nice wall, by the way. Almost white, which was something for such a place as the sewers.

Master Splinter was aghast. If he had heard correctly, and he must have, considering how fine his hearing was, the four turtles in front of him pretended to be coming from… the future? He knew strange things existed in this world. He was one of them, after all. But this… It took all his ninja training to stay calm and focused.

"You four are coming from the future?"

The turtles looked at him, including Raphael, who had hesitated to look at the ceiling instead but decided against it. Too obvious.

"Hai, Sensei," they answered in unison.

Master Splinter took a deep breath and stood. "Stay here." If it was true, four other turtles were currently in the lair. He was going to check up on them.

No sooner had he left the room than the four teenagers began to speak all at once.

"This is bad. This is really bad. I have no idea what happened. I need to calculate everything again and I don't even have all my equipment here and…"

"I knew it was a bad idea! I told you so, but did anyone listen? No! "You're just being pessimistic, Raph", "Relax, Raph", and now you see? See?"

"Owww, guys! Do you think we could take a look at ourselves? How old are we here, anyway? I must be so cute!"

"What are we going to tell sensei? We can't tell him about the Kraang… or the Foot…or Shredder…or April, or Casey, or anything at all!"

They stopped talking and looked at each other. Leonardo sighed. "OK, Donnie. What can you tell us about our current predicament?"

"Not much. We are still in our dimension, only a few years in the past." Donatello looked at Michelangelo. "We should be around fourteen here. I need more time to figure this out. In the meantime, we have to be as discreet as we can to avoid…" The purple clad turtle thought carefully about his next words, trying to keep his explanation as simple as possible. As much as he enjoyed confusing his brothers with scientific and technical jargon, now was not the time. They had only minutes before Master Splinter came back. "… disturbing anything important in our timeline."

"So we don't say anything about our present and we don't interfere with our past selves. So far, so good," said Leonardo hopefully. Raphael rolled his eyes at this statement.

At this instant, Master Splinter came back in the room. He had to accept there were now eight turtles in this lair. Four from the future and four from his present, right now arguing with each other about a TV show. From what he had just overheard, a new episode of _Space Heroes_ , Leonardo's favorite cartoon, was about to begin. Raphael thought it was lame while Michelangelo was ready to watch anything. Donatello had exited his lab to share his disappointment at the way science was used in the show, because there was no way Captain Ryan's spaceship could exceed the speed of light. He had nonetheless taken a sit on the couch to watch the new episode. The ninja master sighed and reported his attention to the four turtles watching him.

"I believe your story, though it is much…unexpected. By the way, what _did_ happen to your voice, Leonardo?"

The aforementioned turtle fought desperately for a suitable answer. He knew that " _I was beaten by our most dangerous enemy, the Shredder, after taking down his minions on my own on a very cold night during an alien invasion. I spent months in a coma. When I woke up, I discovered that my throat had sustained permanent damage,"_ while entirely true, was not a suitable answer. Wait… maybe he could keep the cold night part.

"I caught a nasty cold, sensei," he explained, trying to ignore Raphael's gasp at his side. He knew he was a poor liar, but prayed that his sensei would let him go with it. For now.

"I see… It must have been a nasty cold indeed," Splinter answered slowly. He went on. "What happened for you to be here and now?"

Three of his sons looked at the last, genius one.

"An experiment kind of went wrong. Sorry for disturbing you, sensei. We will be on our way to fix this now!"

The ninja master frowned.

"On your way? What do you mean, on your way?"

"Uh… I need some data to process from a certain… place… on the surface?" Donatello had whispered the last few words. Master Splinter looked intensely at him. Sensing that this wasn't going very smoothly, Donatello looked pleadingly at his brothers. Michelangelo decided to help him.

"Yeah, you know, we go, find whatever Donnie needs and come back. Piece of cake!"

"We won't be seen, sensei," Leonardo added carefully.

"We do this stuff on a regular basis after all," Raphael said with his most convincing tone. The four brothers looked at their father in expectation.

Splinter couldn't believe his ears. Let his precious sons go to the surface? On their own? Even if those were not exactly the turtles he knew, even if he admitted they were older, he wasn't prepared to allow this.

"No, my sons. You cannot go to the surface. This is too dangerous. What if you are seen? What if somebody tracks you down here?"

"It won't happen, sensei," Donatello said desperately.

"Yeah, it won't!" Michelangelo added. "I mean, we have been seen in the past… by people and non-people… But it won't happen this time! Oh, and someone did track us down here once, thanks to Raph, but he was a friend in the end, so it is cool! And we destroyed the evil robots who had followed him, and…" Mikey became suddenly aware of the murderous looks his three open-mouthed brothers were directing at him, and stopped talking.

"You are right, Michelangelo," Master Splinter said with the utmost exterior calm. "It won't happen this time, because you are not leaving the lair."

"But sensei, we have to come back to our time!" Raphael exclaimed.

"And it would be better if our past selves… your present sons, that is, didn't know of us," said Donatello.

"We are really stealthy," added Leonardo.

Master Splinter frowned. He wasn't going to allow them to leave, but he believed that some compromise would do more good than a simple refusal.

"If that is the case, my sons, why don't you prove your stealth to me? If you can stay here, in the sewers, for an entire week without being noticed by your younger selves, then I will reconsider. In the meantime, you are not allowed to leave this place."

His four ninja sons looked at each other in disbelief and horror.

"We are doomed," whispered Mikey.


	3. Mission Pizza

**Chapter 2: Mission Pizza**

Four very distressed teenage mutant ninja turtles sat in their father's quarters. Master Splinter had resumed his meditation in the dojo, leaving them alone. Raphael was the first to speak.

"Is he serious? We have to avoid our past selves for an entire week, and we can't leave the lair? How is it even possible?"

"He wants us to prove our stealth," said Leonardo hesitantly.

"Oh come on, Leo! This lair is not big enough for eight of us!"

"Raph has a point, Leo," said Donatello. "This is insane."

"Maybe not!" Michelangelo intervened helpfully. "We are ninja after all… The greatest heroic ninja team of the whole universe! This is just another of our wonderful adventures!"

"Replace wonderful by crazy and I may consider agreeing with you," added Donatello.

"Point is, we have to make it. Or do you want to try and ignore Master Splinter's orders? I don't think we can stay undetected by our past selves if he beats us to the ground," expressed Leo. The other three looked at him with grim expressions. Their beloved sensei was very much able to do so. He had proven it on more than one occasion. Encouraged, Leonardo carried on.

"All we have to do is to remain silent at all times and avoid being in the same rooms at the same time. We are stealthier now than we were at fourteen, and we know what is going on, which they don't. We can do this, guys."

"Fine," Donatello sighed. "But it is going to be a tough week."

Raphael wasn't going to agree that easily.

"All we have to do is to remain silent at all times? Hello there! Here is Mikey, your brother who can't even stay silent when we infiltrate an enemy's lair…"

"Hey, Raph! Not cool, dude!" Michelangelo protested. "I'm only using my amazing deception talents to lure the enemy into thinking we are clumsy."

"I am sure Mikey can stay silent if he wants too," Leonardo said soothingly, if not entirely honestly. "And our past selves won't stay all the time in the lair, either because they will want to have fun in the sewers or because they will…" The blue clad turtle interrupted his speech mid-sentence and paled.

"Leo, are you alright?" asked a curious Donatello. "What were you going to say?"

Leonardo blinked in his brother's direction and took a deep breath. Very slowly, very carefully, he finished his sentence. "Because they will scavenge for food."

Donatello looked at him curiously. Then he understood. "Oh my…"

"What is it?" Both Raphael and Michelangelo exclaimed.

Donatello and Leonardo looked at each other, and the purple clad turtle went on. "Scavenge for … you know… algae and worms…" He then closed his eyes, not wanting to see his brothers' reaction. Especially Michelangelo's. Leonardo, on the other end, watched his brother very carefully, and was ready when Mikey opened his mouth to shout. He quickly covered it with his hand.

"Oh, I see," said Raphael in disarray. "We didn't know pizza existed when we were fourteen…" He thought about it for a few seconds and looked at Leonardo with something very close to glee in his eyes. "And how are you planning to keep Mikey away from pizza for an entire week?"

Leonardo's hand was still on Mikey's mouth. The orange clad turtle's eyes were filled with sheer horror and fury. He answered quickly. "I am not planning to do such a thing. Okay, Mikey? We will find a solution." With that, he finally released his brother.

Michelangelo did a fair job in keeping his furious tone at a reasonable level. It was nonetheless a blessing that the _Space Heroes_ episode was still on at full volume.

"I am not eating algae and worms pudding for an entire week. This is not happening. It is totally impossible, guys! And now that I think about it, I am hungry right now. And I want pizza. A good old peperoni pizza." His tone became pleading. "Please?"

"Do we even have money to pay for it? I don't. I wasn't planning to leave for an entire week," Donatello muttered.

"Yes, I do," said Leonardo, and his brothers exchanged glances.

"This is so not surprising," grumbled Raphael.

"Me too," added Michelangelo. The others looked at him in surprise. "What? You never know when you might need pizza. Or ice cream. I personally need those on a regular basis. This diet keeps me happy and healthy."

"Some ninja," sighed the red clad turtle.

"OK, guys. This is an emergency. We will talk to Master Splinter about it right now," said Leonardo.

"While you guys do that, I will reconfigure my settings for our T-phones firewalls and check the satellite connection, which may be…" Donatello interrupted himself and sighed. His brothers were wearing nonplussed expressions. "Or the T-phones won't work here. And we won't be able to order pizza."

"Dude, why didn't you just say so?" Michelangelo asked.

A few minutes later, Leonardo, Michelangelo and Raphael were trying to convince their father to let them go in the sewers in order to retrieve their pizza. Master Splinter lifted a brow.

"This pizza, it is a kind of food, right?"

"Not just a kind of food, sensei!" Michelangelo exclaimed. "It is the best food ever! I can't live without it. I would die from starvation in a few hours. Please, please, please!"

"Do you mean that algae and worms are not good enough for you anymore?"

Michelangelo winced at the trick question. "No, not at all! I mean… yes, but I loved algae and worms! When I was little, that is. Now I am all grown up and I need a more nourishing food, to keep my spirits high and my stomach happy!"

"Do you mean that algae and worms are not nourishing enough for you anymore?"

"Uh, I…"

Leonardo decided to intervene. "Please, sensei. Our alimentary habits have changed since then. Of course we are very grateful for all the algae and worms you gave us over the years, but things change. And change is good, right?"

Raphael entered the conversation. "And we really can't prevent Mikey from eating pizza. Even if we bound him and knocked him out," the red clad turtle caught his father's glance and quickly added, "…not that we would ever do such a thing to him. But in the very improbable case that we would, he would still find a way to sneak out and get some pizza."

"Yes I would," said Michelangelo proudly.

"So, what do you say? We won't leave the sewers. Our food will be delivered at a drain only ten minutes from the lair," finished Leonardo.

Master Splinter looked at his sons and sighed. This pizza really seemed to be a matter of life and death.

"Fine…" His sons cheered up. "But I must come with you."

"What? We don't need you to babysit us!" Raphael answered without thinking.

"What was that, Raphael?"

"Uh… Nothing, sensei. I meant, of course we will be very happy and honored if you would accompany us, your presence is always welcome at any time!"

"Nice save, Raph," whispered Leonardo, suppressing a smile.


	4. So Far, So Good

_Author's Note: Wow, there are actually people out there who like this story! Thank you so much! Here comes the next part._

 **Chapter 3: So Far, So Good**

An hour later, the four turtles had their pizzas. They had waited for their younger selves to go to the kitchen for an algae and worms meal before retrieving their own food, along with Master Splinter who didn't want to let those enthusiastic teenagers from the future out of his sight. Mikey was satisfied with the deal. It meant he would get some proper food. Each of the other three was secretly relieved that they would avoid algae and worms pudding, too. Who could have blamed them?

They ate their pizzas quickly and carefully on the ten minutes it took them to get back to the lair. The 'quickly' part was entirely normal. The 'carefully' part…not so much. However, they didn't want to leave any clue about this strange situation for the other turtles, and bits of pizza or empty pizza boxes definitely qualified as clues. If Master Splinter was somewhat surprised by this new food and by his sons' efficient but revolting way of eating it, he said nothing of it.

When they arrived at the lair, voices could be heard from the kitchen where the four younger turtles were still eating.

"Are you already done? You have some pudding left, Donnie."

"You can finish my plate, Mikey. No problem at all."

In the main room of the lair, an older Michelangelo glared at his own Donatello.

"You never say such nice things to me anymore," he whined.

The four turtles quickly grabbed some items to help pass the time. Michelangelo took a game console and some video games. Raphael chose a comic book. Leonardo took an old newspaper. Donatello went for his lab. The whole situation was getting on his nerves. He needed to work on something mechanical or he would go crazy. Of course, it had to be something his past self wouldn't need. The purple clad turtle glanced at his desk. _What was I working on at the time? Hmm, I think it was this new computer. Yes. Good thing I have an excellent memory._ He snatched some tools that weren't required for building the computer and an old radio discarded in a corner before leaving his lab.

During the next few hours, eight turtles stayed in a relative quiet. Four of them were in the dojo, moving in the corners or behind the tree each time someone approached the entrance. Leonardo had somehow managed to convince Michelangelo that it was not a good idea to let the volume of his video game on, _no way, Mikey, as soon as we are back I am going to hide all your comic books if you don't turn it off right now_ and he was reading his newspaper looking for clues from the Kraang's presence in New York City. Moreover, any information about the time they were stuck in could later prove useful. Donatello was busy with his radio, absent-mindedly wondering how he would fix his device when their sensei would finally allow them to go to the surface and retrieve the information he needed. He suddenly dropped his screwdriver and wondered curiously if the noise it would make when hitting the floor was enough to attract unwanted attention. Raphael caught it in mid-air without looking away from his comic book.

"Less thinking, more action," he deadpanned.

By then, it was time for evening training. Luckily for the four turtles of the future, their past selves were gathered in Donatello's lab and they were able to retreat safely towards the rooms. They heard Raphael's voice coming from the lab.

"What do you mean you can't find my radio? You were supposed to repair it last week!"

Donatello's voice answered.

"I have no idea, Raph! Ask Mikey, he is usually the one who tinkers with objects which don't belong to him."

"Hey, that's not cool! I didn't move your radio… At least I don't think so…"

"Let's get to the dojo, guys. We don't want Master Splinter to wait for us," Leonardo cut them off before they could start fighting. Again.

In the dark corridor, Michelangelo looked at his brothers, then at the radio still in Donatello's hands.

"Looks like someone owes me an apology."

Donatello had the good grace to look sheepish.

Training was funny to watch. At least, Raphael thought so. Master Splinter had decided to make their younger selves spar one to one. Michelangelo and Donatello were sparring against each other while Leonardo was against Raphael. The older Raphael grinned when Leo went to the ground for the fifth time in the past three minutes. _I have missed this._ He spared a glance at his own Leonardo, who was watching him as if he knew exactly what he was thinking. Proving his point, the blue clad turtle mouthed the words "I haven't."

"Wow, I had forgotten how smug Young Raph could be during training," whispered Michelangelo next to them. "But you have to give it to Young Leo, he doesn't give up."

"Young Raph? Young Leo? Seriously?" Raphael grimaced.

"I suppose it is fitting," answered an amused Donatello.

"As long as you don't begin to call me Old Leo, I can live with it," sighed Leonardo, and Michelangelo beamed at him.

"Whatever," whispered Raphael. He was still in a very good mood, which only went better when the young Leonardo hit the ground again. "I have to go."

Raphael was heading for the bathroom when he spotted a familiar sight. He felt his heart ache. In the doorway of his room was his pet turtle Spike. He hadn't seen him since he had caused his mutation into a giant and furious turtle who had tried to kill his brothers. He shivered at the memory. _Not that I intended for it to happen,_ he thought. _And Donnie is to blame too. He can be so careless with his stuff at times._ But this sweet, little turtle was chewing a tiny leaf and Raphael wanted nothing more than to take him in his arms and muzzle him. He sent a quick glance around him. He was alone. His brothers were still watching the training session. He smiled slightly and lifted the small turtle with all the care and love in the world.

"Hello, Spike," he whispered. "Long time no see. I have missed you, buddy."

The turtle pet was looking at him with blank eyes. He went on in a hesitant tone.

"I know I have a bad habit of complaining about my brothers, but I still care about them, you know? There are not that bad. Not all the time, at least. Just saying."

He interrupted himself. He had spent years and years telling Spike how much better he would be without his lame brothers. Maybe he had to be a little more explicit right now.

"In fact, what I am trying to tell you is that I really love th…"

Raphael suddenly felt observed and turned slightly. _Oh come on._ Now he was ready to disappear from this lair, this city and even this planet, Master Splinter or not. His siblings were here, a few feet away from him. They had obviously heard his last sentence. Their open mouths and wide eyes were proof enough. Raphael felt his cheeks burn and took his most menacing, don't-you-dare-contradict-me deathly tone, and spoke.

"This never happened."

Donatello was the quickest to recover.

"What are you talking about? What happened?"

"Yes," added Leonardo, "I have no idea what you mean." He was proud that his voice was almost not trembling with the beginning of a hysterical laughter. He had no death wish, after all.

"Dude, of course this never happened… I mean, nothing never happened…uh, ever happened," expressed Michelangelo, his eyes shining with mirth and mischief. "But if it had… if it had…" He almost choked. "It would be so cute!"

He dived behind Leonardo when Raphael came stomping at him in an even so impressive silence.

 _Smack_.


	5. Spying On You

**Chapter 4: Spying On You**

Three days had passed since the arrival of the turtles from the future and Master Splinter was still struggling with the concept. He had discreetly observed them interact with each other and hide successfully from their past selves. Master Splinter didn't exactly know if it was talent or sheer luck, but the younger turtles were completely oblivious to the recent events. _My bet is on the second possibility,_ he thought wryly. In a corner of his wise mind, he knew that he wasn't giving his sons enough credit. However, he could hardly consider them as more than immature younglings. The fact that they were arguing with each other on a regular basis didn't help. _At least they do it almost silently, which is a welcome change,_ the rat master chuckled.

He was still accompanying his older sons when they retrieved their ordered pizzas, to Raphael's ill-concealed dismay. _Even if algae and worms are much better food,_ he thought ruefully. However, he hadn't properly discussed with them since the first day. He would have liked it. He was curious to know how they had evolved and if his lessons at life in general and ninjitsu in particular had borne fruit. He didn't even know how much older they were. They looked pretty much the same. He sighed. He had four more days before having to reconsider his decision to lock them up in the lair. An overprotective part of him hoped they wouldn't make it this far. Maybe he should challenge them more…He hummed and resumed his meditation.

The four older turtles were adjusting slowly to their new way of living. It was strange for them to remain quiet at all times and to stick to the shadows in their very home. Each of them dealt with it in a different way.

What Michelangelo found most difficult was to stay quiet. He found such happiness in shouting and exclaiming and generally breaking every quiet atmosphere that he almost couldn't bear not to speak loudly. He was sick and tired of whispering and he was beginning to get really, really bored.

He had developed a new game to help pass the time. He would cunningly displace some objects around the lair to get one of the younger turtles in trouble. He was especially proud of his last prank. He had displaced Young Leo's katana while he was busy watching a _Space Heroes_ episode and hidden them near Young Raph's punching bag while Young Mikey and Young Donnie were scavenging out of the lair. It had been fun to watch Young Leo when he had noticed the absence of his beloved weapons and searched for them in the entire lair. He had accused Young Raph of stealing them and when the red clad turtle had roared in outrage at the unfair accusation, the situation had quickly escalated into a full and very entertaining argument. Master Splinter's intervention had been necessary to calm them down. Michelangelo was very satisfied with himself. If he couldn't be noisy, then he would make sure others kept a satisfying high volume in his home.

Unfortunately for him, his own Leonardo and Raphael had caught him. It was an understatement to say that they had been less than happy with his actions. He had tried to explain his reasons to them, but somehow they hadn't considered them as valid. The poor orange clad turtle sighed. He would have to find another way to avoid boredom. _Well, I will just have to wait for the right opportunity and follow my amazing imagination into satisfying trouble,_ he thought to himself.

Donatello was mostly focusing on trying to understand what had happened to them. _What did I miss?_ He was wondering during the long hours he had to spend out of his lab. This was torture, by the way. Seeing his lab so close and being forbidden to use it was driving him crazy. He turned his thoughts back on the device that had brought them here and now. _It was supposed to be a short-range teleportation device_. _Mikey had talked me into this because he wanted to offer Ice Cream Kitty a way to move around the lair and still be able to get back in the fridge in seconds._ No one could resist Mikey when he was begging with his puppy eyes for the sake of another creature, and Donatello was no exception. This ability of Michelangelo had once caused them to bring an insane giant alligator home. _And this time it was for Ice Cream Kitty, which is way sweeter than Leatherhead_ , the purple clad turtle reasoned.

The problem was that he had no idea how to proceed. He had used an alien technology to build the teleportation device. The Kraang were much more advanced than the humans, but they didn't time-travel. _Maybe they have made some kind of breakthrough_ , he thought. _If that is the case, they must have had a research project on the subject for years. We have to check that and we can only do it if we are allowed out of this lair. We can do it. We are almost at the midway point of this whole stupid challenge._

Raphael was becoming restless. He wanted desperately to go out and breathe the wonderfully polluted air of New York City. More than once, he had considered leaving the lair for a little while. However, every time he had approached the entrance of the lair with those thoughts, Master Splinter had materialized out of nowhere. _His sixth sense is freaking me out_ , thought the red clad turtle. _Does he have telepathic abilities?_

Nonetheless, he found that the situation had some advantages. First, he could see his pet turtle Spike again. Second, he rather enjoyed himself when he watched the younger turtles' training. At the time, he had always won his fights against his brothers. _I still do, at least against Donnie and Mikey,_ he mused. Leonardo was another matter. His brother had really improved during the past few years. He didn't resent him anymore, though. _It is fun fighting against Leo, but it is more fun fighting with him against the Kraang, and the Foot, and all those wild mutants. I miss the action,_ Raphael sighed inwardly. He would be delighted at the end of the week, when their sensei would have to recognize their amazing abilities at stealth. _If Mikey doesn't mess up before that,_ he thought glumly. _I can't believe that he has been deliberately trying to attract trouble by stealing Young Leo's swords. Or that he would get_ my _past self in trouble for it. What does he have in mind now?_

Leonardo was having similar thoughts. The blue clad turtle was worrying a lot these days, which was saying something. He knew his brothers well enough to expect trouble before the end of this fateful week. In fact, it was a miracle that they had gone this far. The earlier Mikey episode had only confirmed his fears. He had been furious against his brother for so carelessly risking their cover. But if he was truly honest with himself, he was more ashamed with his past self. _He didn't think this through,_ he thought sadly. _He was so mad that he didn't even give Young Raph a chance to speak. It was stupid, and it was wrong. And it hurt Raph._ Leonardo sighed. _Was I really that oblivious to my brother's feelings? Have I changed that much in the past few years?_

And there was Master Splinter. Leonardo used to come to him every time he needed to talk. He had missed his father a lot when he had been recovering in Northampton. Right now, he wanted nothing more than to share a cup of tea with him and tell him everything they had experienced in the past years. Of course, it was impossible. On the contrary, he had to stay away from his sensei to avoid disturbing the past. It was hard on him.

Besides, he missed training. Of course, he was occasionally performing katas. However, he was unable to concentrate fully on what he was doing because he had to remain aware of the younger turtles' whereabouts at all times. He couldn't spar with his brothers either. He made the best of the situation and took it as an intense training in stealth.

All in all, the four turtles were coping with the situation pretty well. However, things were about to become more complicated.

It happened during the evening training of the four younger turtles. The older turtles had taken the habit to watch them from the doorway. This time, Master Splinter had begun the training with a meditation session, which forced the four spies to remain completely silent. After that, the rat master had given the subject of the lesson.

"My sons, tonight you are going to learn to listen to your surroundings more carefully. A ninja must remain aware at all times. You never know what can be happening right under your nose."

Outside the dojo, Leonardo couldn't believe his ears. It had been hard enough to remain undetected for the last three days, and now Master Splinter was handing their past selves a clue that things weren't right in the lair? Their sensei wasn't playing fair. Next to him, Raphael shook his head in disbelief.

Oblivious to his sons' dismay, Master Splinter went on.

"You will begin with closing your eyes and performing simple katas. Keeping your eyes closed will force you to rely more on your senses of hearing and smell. Focus on your environment."

The four younger turtles nodded and began the exercise. They were soon moving carefully through the dojo.

 _This is the entertainment opportunity I have been waiting for,_ thought the older Michelangelo happily. Before his brothers could stop him or even register what was happening, he sneaked inside the dojo and stood behind the younger turtles, mimicking their slow movements with jubilation. He looked at his brothers standing in the doorway. Their faces were priceless. Master Splinter was looking at him with a raised eyebrow, successfully hiding his surprise. _A bold move, but not a very wise one,_ thought the amused rat master.

"Watch it, Donnie!" Young Raphael exclaimed when his brother accidentally bumped into him.

"Sorry, Raph!"

Both had opened their eyes and were looking at each other. The young Leo and Mikey were slowly turning to see what was happening. It was a matter of seconds before they saw the other Michelangelo, who was too far from both the tree and the door to escape. The orange clad turtle knew he had pushed his luck too far and sent an apologetic glance at the door.

 _I can't believe it,_ thought the older Leonardo. _I can't believe it. I really,_ he moved fast behind the young Mikey and tripped him, knocking him against the young Raph and Donnie, _really,_ he circled the four turtles and tripped his younger self, sending him tumbling to the three other turtles, _can't believe it._ He looked at his Michelangelo and nodded in the direction of their sensei. His brother closed his open mouth and nodded, understanding immediately.

"Not fair, sensei!" The orange clad turtle said aloud so the other turtles would believe it was Master Splinter's doing. _I hope_ _Young Mikey is too busy right now to wonder who is speaking,_ he thought.

Fortunately, the young Michelangelo was indeed too busy to notice. He was, after all, trying to disentangle himself from the ball of turtle limbs rolling and shouting on the floor.

The older Leonardo took his Michelangelo by the arm and both of them disappeared from the dojo. Master Splinter shook his head in amazement. Maybe he had underestimated his future sons' resourcefulness.

"Yame!" He shouted to stop his younger sons' fighting.

The four ninja turtles interrupted their wrestling and looked sheepishly at him.

"This is why you have to remain aware of your surroundings at all times," the ninja master concluded quietly.


	6. Close Call

_Author's note: I'm glad you're enjoying the story! Thank you for reviewing! Let's see what happens now…_

 **Chapter 5: Close Call**

The younger Raphael walked out of his room and yawned. It was the middle of the night and he was thirsty. Michelangelo had tried a new recipe tonight, one which involved algae and worms and a lot of salt. He headed for the kitchen to retrieve a glass of water. Half asleep as he was, he didn't bother to switch the light on. He was passing by the main area of the lair when he saw someone rummaging through his pile of comics. He growled sleepily.

"Mikey, I have already told you that you have to ask before borrowing my…"

He interrupted himself abruptly when the accused turtle straightened up. This wasn't Mikey. And this wasn't Donnie or Leo, either. This turtle looked exactly like himself. _I must be dreaming,_ he thought.

"I must be dreaming", he said aloud.

The other turtle was looking at him with both surprise and annoyance, as if _he_ was the intruder here. But this other version of himself didn't seem to be able to answer, or make a move. He just stood there, helpless. _What is going on here?_ The younger Raphael wondered, bemused and unwilling to believe his own eyes.

The older Raphael was at a loss. He had no idea what to say. The four future turtles took turns at night to be sure they would be able to react in time if one of the younger turtles got up. _Like right now,_ he thought bitterly. It was supposed to be his watch. To be precise, it was the end of his watch and he was both tired and bored. He had been reading a comic book in the dim light of his T-phone and was replacing it in its pile when he had been spotted. _By no other than my younger self,_ he thought furiously _. If it had been Young Leo, or Young Donnie, or Young Mikey, I could just have pretended to be their Raph. But no! It had to be me!_ He was slowly beginning to panic. What could he say? What could he do? How could the truth remain hidden now that this Raphael…

"Of course you are dreaming!" A new voice answered, interrupting the older Raphael's panicked thoughts. Both him and his younger self recognized Donatello's voice and turned to look at the purple clad turtle.

The older Donatello's heart was beating fast. _This is bad._ He had awoken a few minutes earlier. He was taking the next watch, so he hadn't tried to fall asleep again. He had witnessed the younger Raphael coming out of his room and heading for the kitchen, and prayed that he didn't spot his own Raphael. _It was a vain hope, obviously._ His Raphael had been frozen in shock and obviously unable to respond appropriately to the situation. So Donatello had decided to step in.

"This is all a very strange dream," a very distraught Donatello went on. "So… what about you go back to bed to finish it comfortably?" He added rather lamely.

Young Raphael was becoming suspicious. His dreams weren't usually like this. And why should he go back to his bed if he was already sleeping in it?

"You know," he began quietly. "If it is a kind of joke… or one of your messed up experiments…"

 _Oh no_. _I can't let him begin to actually think about the situation. I have to persuade him that he is dreaming,_ Donatello thought as fast as he can. And for the record, he could think really, really fast. _What could convince him that he is really dreaming? What kind of impossible event… something not related to a scientific experiment so he will stop suspecting me… something so improbable than he would never accept the reality of it…_ Suddenly, an idea came to him. It may have been a crazy idea, but it was an idea nonetheless. Donatello took a deep breath.

"No, it is just a dream. A dream in which you fight me with all your strength and…" Donatello forced himself to go on. "…and I win."

Young Raphael immediately focused his attention solely on him, forgetting the other Raphael's presence.

"Not even in my worst dreams would such a thing happen," he uttered with conviction and a touch of his well-known anger.

"It would, in a really bad nightmare," added Donatello. He felt slightly offended, though.

Young Raphael smiled menacingly at him.

"Nah, a dream in which I get to fight you is not a nightmare. At least not for me!"

With that, he advanced threateningly in Donatello's direction. The genius gulped. _Well done, Donnie. And now you just have to defeat a mad Raphael without awakening anyone else._ He dodged the first blow. _I am much better than I was at fourteen. I am more experienced, faster, stronger. I can do this._ Young Raphael gave his legs a nasty kick and Donatello jumped just in time to avoid it. _Except for one thing,_ the purple clad turtle realized with horror. _Thanks to my clever plot, he really thinks he is dreaming. So he won't restrain himself out of fear of hurting me._ Donatello grimaced when his opponent landed a blow on his shoulder. _Ouch! That hurts._ The taller turtle sighed inwardly. _Time to put my theory into practice, then._ Hoping his skills would be enough, he launched a counterattack.

The older Raphael witnessed the fight with disbelief. _Donnie is crazy,_ he thought. _He may be better than my younger self at ninjitsu now, but Young Raph isn't going to play by the rules. This is going to be a brawl, not a sporting match._ However, he knew he couldn't interfere with it now. Donatello had to defeat the younger Raphael to save their cover.

Donatello was having a hard time keeping up with Young Raphael's pace. When the younger turtle was just enjoying his dream and landed as many blows as he could, the purple clad turtle was trying to keep quiet and to avoid hurting his brother. It went worse when the red clad turtle began to tease him.

"You know, Donnie, I think I really enjoy this particular nightmare," he said wryly.

Donatello gritted his teeth and didn't answer.

"Look at it this way," Raphael went on. "At least in my dreams you put up some fight. It's a pity you can't do that in the real world!"

The purple clad turtle exhaled and thought furiously. _He doesn't think it is real. I can't blame him for what he says in his dreams. He doesn't think it is real…_

"Yeah, this is really not so bad," Raphael added. "And I thought you fought no better than the damsels in distress of Mikey's cartoons!"

The mention of a damsel in distress made Donatello think about the very first time he had seen April. He had saved her that night. His skills had been enough. He had saved her… and on numerous occasions after that, he had saved his brothers too… he was stronger, he was more _determined_ …

Young Raphael didn't see the blow which sent him to the ground. One second he was grinning at his brother and enjoying his fight, and the next he was sprawled on the floor. He looked at Donatello in disbelief.

"You…won?"

"I told you it was a bad nightmare", his brother said calmly. He didn't manage to completely hide his triumph, though.

Young Raphael's vision blurred. With a growl, he stood up and took a screwdriver his Donatello had let lying down on the floor. Before he could send it at the unsuspecting older Donatello to make him disappear of what he thought was a dream, the older Raphael moved forward and knocked his younger self out with one precise blow.

Donatello blinked.

"Uh… Thanks, Raph."

"Sure thing, Donnie. Now help me get him back to bed," Raphael answered very quietly.

After this was done, the two future turtles walked quietly back to the dojo.

Raphael was the first to speak.

"You know, Donnie. When we will be back home… What about you don't tell April and Casey what happened tonight and I don't tell April that the mention of a damsel in distress made you think of her," Raphael threatened. "Deal?"

"How do you know it was that?" His brother stammered. Raphael looked at him knowingly and quite menacingly. Donatello thought he heard him whisper something along the lines of _And what else could it have been_ and sighed. He would have liked to boast about his victory tonight, even if it was against a younger Raphael. But there was no telling what April would do to him if she heard about the damsel in distress thing. A mad April was not a pleasant sight to witness.

"Deal," he whispered sadly.

They entered the dojo where their two other brothers were sleeping. Or more exactly, were supposed to be sleeping.

"Nice job, guys," Leonardo greeted them with a wide smile despite the fact that this night could have ended up in disaster.

"Now that was the best show I have seen lately," chirped Michelangelo.

Raphael narrowed his eyes and elbowed Donatello with strength.

"Ouch! What was that for? I saved the night! And I won fair and square!" Donatello protested.

"You also forced me to knock myself out. And about your victory…" Raphael paused. "Yes, you won the first round. Now I want a rematch, and I want it now!"

"Guys, the stage is all yours," grinned Michelangelo as he and Leonardo stepped back.

Donatello growled. _I knew I should have gone back to sleep._


	7. To Be Caught or Not To Be Caught

_Author's Note: Did someone mention a bombshell? Let's see…_

 **Chapter 6: To Be Caught or Not to Be Caught**

When Young Raphael awoke next morning, he realized that he had a bad headache. He was left with a few impressions of his last dream. It had been a nice wrestling dream, hadn't it? But then something had gone wrong. He couldn't remember what it was. The red-clad turtle shrugged and got off his bed. He would surely feel better after breakfast.

Young Michelangelo was already in the kitchen. He didn't usually wake up this early, but he was feeling restless. There was something strange in the lair, he could feel it. At the beginning, he had thought that he was imagining things. He was doing that a lot. But it was different this time, even if he couldn't picture why. There was a tension in the air, something careful and cautious. Michelangelo was very sensitive to atmospheres. He could recognize all their shades in the blink of an eye. Whether they were happy, funny, awkward, sad, dangerous, lonely, relaxed, relieved or not, he could tell. Of course, it didn't mean that he reacted appropriately each time. That wouldn't have been fun. But the point was, he could tell that something was definitely weird in the lair these days.

Young Leonardo was brooding over Master Splinter's behavior. It had been slightly strange, as if something was off. The rat master was observing them more intensely than usual, as if he was expecting them to… what? _What am I missing here?_ The frustrated blue-clad turtle thought.

On his way to the kitchen, Leonardo heard noise in his brother's lab. He checked the room and found out that Donatello was waking up at his desk, where he had obviously spent the night. _He is going to be in a bad mood today,_ the blue-clad turtle thought amused.

Young Donatello stirred and opened his eyes. He had been in his lab the whole night, advancing some of his most urgent projects. At least, he labeled them as urgent. His brothers weren't always of the same opinion. _They don't understand how important my work is,_ he thought irritated. _Except if it has something to do with TV, or video games, or pinball machines._ He sighed. He knew his bad mood was mostly due to the fact he hadn't slept in a comfortable bed. His muscles were sore. _Breakfast will help. Maybe._

The four teenagers ate their breakfast in silence. Raphael was massaging his head, Donatello was contemplating the content of his bowl with very little enthusiasm, Leonardo was frowning at nothing in particular and Michelangelo wasn't offering his usual jokes.

Finally, the orange-clad turtle looked hesitantly at his brothers.

"Guys? Did I miss something?"

His brothers looked at him expectantly.

"Probably," snorted Raphael. "Can you be more specific?"

Michelangelo stuck his tongue at him and went on.

"I mean, do you feel something strange too?"

"You're imagining things again, Mikey," said Donatello. "The only strange thing I can think of right now is that someone broke the TV remote _again_ and didn't even bother to make himself known before putting it on my desk." He sent his shortest brother a glare.

"This is not strange at all", Michelangelo said quickly, looking sheepish. "This is just the action of a very wise and careful guy. A guy who values his own life, like me. Not that it _was_ me, of course…uh…"

Leonardo came to his rescue and changed the topic.

"Actually, I am feeling something strange too. There is something in the air. I can't figure out what it is, but…"

Raphael cut him off derisively.

"Don't encourage Mikey, Leo. There is nothing strange in this lair. You too are watching too much TV. It is damaging your brain." He paused. "At least your brain, Leo. Mikey would need one to begin with…"

"Hey!" Michelangelo protested.

"I am serious here, Raph!" Leonardo answered with exasperation. "Remember how Master Splinter told us to pay attention to our environment at all times? Well I am, and I tell you something is amiss!"

"Relax, Leo, this is no training. Why don't you focus on your fighting skills instead, so I don't mop the floor with you next time?" Raphael answered sarcastically with a wide grin.

Donatello wasn't in the mood for a fight.

"Relax, guys. Let's take a scientific look at that."

His brothers groaned, but the interruption worked. He went on.

"So two of us are thinking that something is strange, and two of us are thinking that…

"..they are stupid," muttered Raphael.

"…they are mistaken," Donatello continued unfazed. "But as a scientist, I am willing to reconsider if there is enough evidence…"

"You want evidence of strangeness, bro?" Michelangelo interrupted. "No problem at all, I can give you that." He bounced, then stopped. "And, uh…What kind of evidence would that be?"

Donatello thought about that.

"Well, if you can find something that doesn't belong in the lair. Or if you notice someone behaving differently. That would be evidence."

"Okay, then," Leonardo said with a feeling of excitement. "Let's search for signs of strangeness." _Anything but feeling helpless,_ he thought.

"You are losing your time," sighed Raphael. "I'm out of here."

"Donnie, are you going to help us?" Michelangelo asked.

The purple-clad turtle sighed. Mikey was looking at him with puppy-dog eyes.

"Sure, Mikey. It's not as if I have anything more important to do…"

The three turtles spent the rest of the day searching the lair. They didn't find anything unusual but had a lot of fun. They found objects they had thought lost forever, made an impressive mess in the kitchen and ended up in an epic water balloon fight. Raphael even joined them for that last part.

When they sat for dinner, they were in a much better mood than they had been at breakfast. Leonardo and Michelangelo were almost ready to admit that they had been wrong and nothing was amiss.

"So, did you find anything?" Raphael asked smugly.

"A lot of things, in fact," answered Leonardo. "But nothing relevant."

"We should do that more often, it was so much fun!" Michelangelo said happily. "And Master Splinter didn't even tell us off for the mess!"

"Well, that is _strange_ ," laughed Donatello. "Do you think he will join us for dinner tonight? He hasn't lately."

Master Splinter rarely ate dinner with them. The ninja master usually enjoyed a quiet tea in his room in the evening.

"If he doesn't, he will miss my famous worms and algae pie!" said Michelangelo. He was very proud of that recipe.

"It would be a pity." Leonardo made a face. "I will ask him."

The blue-clad turtle stood up and headed for his sensei's room.

"Master Splinter?" He called. "Master Splinter, are you here?"

No answer.

"Sensei, Michelangelo cooked us pie. Do you want to join?"

Still no answer. Leonardo shrugged and left. He wasn't going to enter his master's private quarters without permission. Maybe his sensei was meditating. He hadn't used the kettle recently, so he wasn't having tea. _I could boil some water for him,_ thought Leonardo. _This way his tea will be ready when he needs it._

He was lost in thought when something caught his eye. They hadn't finished cleaning after their water fight and there were a few puddles on the floor. But there was water near the turnstiles at the entrance, too. And they hadn't left the lair today. _Is Master Splinter in the sewers? But why? He didn't tell us he would be scavenging this evening._ The blue-clad turtle frowned and called his brothers.

"Guys? I found something!"

In the sewers, the four turtles of the future were eating their evening pizza. They had had a rough day. For an unknown reason, their younger selves had decided to search the entire lair. It had taken every stealth gift they had to avoid being caught.

Michelangelo was melancholic. An epic water balloon fight had taken place and he could not participate.

Raphael was angry. He wanted to let off steam. _I am sick and tired of staying quiet and confined in the lair. I need to go out._

Donatello was restless. _Such a loss of time… I should be working on that device right now! We can't afford to stay there for too long! The consequences could be disastrous…_

Leonardo was worried. _We still have one day to go. We are almost there. Still, I wonder why all the commotion today?_

Splinter was following them quietly. He had taken great interest in the hide-and-seek game he had witnessed this day. He had to admit that the future turtles had done well. _This four stealth skills are much better than those of my present sons,_ he mused. _But are they good enough? If they do the slightest mistake on the surface, they could be chased and hurt or worse._ He shuddered. _My babies. Why did they grow up so fast?_ He frowned. _And what am I going to tell them if they succeed? There is only one more day before the end of this challenge._

Fortunately for the worried ninja master, he never needed to answer that question. Because in front of the group of four turtles and a giant rat were suddenly four other turtles, who had silently followed a trail of water puddles.

The eight ninja turtles looked at each other with utter surprise.

Young Michelangelo beamed.

"Donnie, do you consider four other us-turtles as evidence of strangeness? Because I can see them right now!"

"I stand corrected", whispered an aghast Young Donatello. "There _was_ something strange in this lair."

"It seems that you have lost, my sons," said a secretly relieved Master Splinter to the four defeated older turtles.


	8. What Do We Do Now?

_Author's Note: Poor turtles. They were so close. What will happen to them now?_

 _PS: special thanks to Pancake for his/her detailed review!_

 **Chapter 7: What Do We Do Now?**

Eight turtles were watching each other in the sewers of New York City. Four of them were trying to understand what was happening. After all, you don't run into yourself every day. The other four were desperate. The very event they had tried so hard to prevent for the past six days had now happened. They were discovered. All their efforts had been in vain. It was too much for the older Raphael. He forgot about the whole do-not-disturb-the-past-to-avoid-wreaking-havoc-on-the-present thing. All he wanted was to breathe some fresh air, away from the lair, away from these sewers crowded with too much reptiles. He shook his head in anger.

"That's enough for me. I have seen enough of this nonsense!"

Before he could move away however, his father had caught his wrist. Even if the touch was gentle, Raphael knew he had no hope of escaping and he let out a frustrated growl.

"And where do you think you are going, Raphael?" Master Splinter asked with a dangerously calm voice.

The older Leonardo sighed inwardly. He had been half-wondering if they should use a ninja smoke bomb and disappear from the crime scene in the hope that their past selves would believe in a collective hallucination. Obviously, it wasn't going to happen. _It wouldn't have been such a good idea anyways,_ he thought morosely. _Even if we had managed to escape, Master Splinter would probably have gone after us. Not to mention we will probably need his help at some point and it usually is a very bad idea to irritate him. And what if we need to be in the lair for Donnie's device to work and bring us home? When he will have fixed it, that is._ Leonardo had no doubt that his genius brother would manage to do that. Right now, he was more concerned with the four flabbergasted younger turtles in front of him.

These four turtles were watching, unsure of what to do or say. Could this really be happening?

"Are you even real, or some kind of illusion?" Young Donatello asked. He advanced and poked the older Michelangelo's plastron with his bo staff.

The poked turtle had quickly recovered. Of course, he was disappointed that they hadn't risen to their sensei's challenge. But he was now determined to make the most out of this situation. The most fun, that is.

"Yes, we are real. Dudes, I have been dying to speak with you for the past six days and…"

"Six days?" Young Leonardo interrupted in disbelief. "You have been there for the past six days? How?"

The older Donatello glared at his Michelangelo.

"Mikey, be quiet! We can't tell them anything, remember?"

"But Donnie," Michelangelo protested, "surely it is different now? I mean, they won't forget about us now!"

Young Raphael was silent. He couldn't believe it. _Leo and Donnie were right after all,_ he thought. He looked at his other self, trapped in Master Splinter's grip. _This is the strangest thing I have ever seen. Why do I have the feeling that it's not the first time, then?_

Young Michelangelo couldn't contain his excitement much longer and ran to the four turtles in front of him. He hugged each of them in turn with delight.

"Amazing! You look just like us! And you smell just like us, too! So where are you from? What are you doing here? And what is", he sniffed, "this delicious smell?"

"Dude, what you're smelling right now is the meaning of life itself!" The older Michelangelo was delighted. "It is called pizza, and I shall introduce it to you…"

"Mikey!" The older Donatello shouted. "You can't disturb the past like this!"

The purple-clad turtle understood his mistake too late.

"The past?" His younger self frowned at him. "You are from our future? You are… us from the future?"

"No!" The older Donatello protested lamely.

"Yes!" The older Michelangelo agreed happily.

"Sensei, did you know about them?" Young Leonardo asked his father. He felt a little hurt that his father had said nothing. _Six days, really?_ And his other…older self wasn't even looking at him. _Why does he say nothing?_

"Yes, my son." Master Splinter answered seriously. "I suggest that we continue this conversation in the dojo. Raphael, can I trust you not to run away?" He asked his trapped son.

"Yes, Master Splinter," sighed the red-clad turtle.

The nine mutants went slowly back to the lair. Once in the dojo, the turtles settled in two lines of four, facing each other. Master Splinter stood between them.

"My sons and… my sons, I understand that these circumstances are rather extraordinary. However, I ask you to remain calm. Maybe," the rat master turned to the future turtles, "one of you would care to explain what is going on?"

The older Michelangelo, Donatello and Raphael turned slightly towards their Leonardo. The blue-clad turtle sighed. He hadn't spoken until then. _There it goes again,_ he thought, preparing himself for what would undoubtedly come.

"We are indeed from the future," he began. He was immediately interrupted.

"Leo! What happened to your voice?" asked Young Michelangelo, Donatello and Raphael in dismay. Young Leonardo didn't join them. He had never heard his own voice from outside and couldn't tell what was wrong with it.

"I caught a nasty cold", the older Leonardo lied for the second time this week.

"Yeah, a naaaaasty cold," said the older Raphael with as much irony as he dared to muster. He felt his Leonardo tense at his side and immediately regretted it.

"I don't think that a cold could…" began Young Donatello. His older self sent him a warning glance and he stopped. "Or maybe it could," he added, blinking. _I wonder what the true story is,_ he thought _._

"Anyway," Leonardo went on. "We landed by accident here, in our past. We have been trying to avoid you so we won't mess up our present. We are sorry it didn't work in the end, but you have to understand that we can't tell you too much." He eyed his Michelangelo carefully. He had a feeling this wasn't going to be easy.

"Technically, we already messed up our present." The older Donatello sounded desperate. His Leonardo tilted his head and narrowed his eyes. _Or do you think otherwise, Leo?_ The purple-clad turtle felt a flicker of hope.

"Actually," the older Leonardo said, "I am not so sure about that."

He looked at the four younger turtles in front of him and went on hesitantly.

"It is something that Mikey… my Mikey… said earlier. That you "won't forget about us". But we don't remember you, so either the past is already altered beyond repair or there is another explanation, and somehow you…we… forgot about this whole experience."

"I don't see how I could possibly forget about that," snorted Young Raphael.

The older Raphael said nothing. _You are not telling us everything, Leo. What do you have in mind, you sneaky turtle?_

Both Donatello were pondering this.

"Amnesia is a possibility," the older Donatello said slowly.

"But it would have to be induced by some kind of trauma," added Young Donatello thoughtfully.

Master Splinter frowned. He didn't like the sound of it. The ninja master looked at his eight sons. All in all, the four younger turtles were taking the news pretty well. Or maybe they were still in shock, he couldn't tell. Now he had to decide what to do with his four older sons. He addressed the younger turtles first.

"My sons, you may leave. I wish to speak with my older sons in private."

The said turtles left without complaint. They needed time to process what was happening.

"My sons." Master Splinter went on, looking very seriously at the four future turtles. "While I have been impressed by your stealth skills, you didn't stay hidden for an entire week as we had agreed upon."

The four ninja turtles looked down.

"That is why I cannot allow you to go to the surface." Master Splinter added.

Donatello looked up.

"But sensei, we need to go back to our time! And for that, I need data that can only be found on the surface!"

"Are you sure that this data would allow you to go back to your own time, my son?"

"No," Donatello had to acknowledge. "But it is our best chance."

His four sons were looking at him with puppy-dog eyes. Michelangelo's were the best, but his brothers' were almost as good. Master Splinter felt his heart melt.

"How long would it take to retrieve this data?" He asked carefully.

"Less than an hour, I think." Donatello couldn't believe his ears. Finally, finally! Their father would let them go out! He understood! He trusted them! He…

"In that case, I will go with two of you to the surface and we will retrieve the data you need."

"What?" The four turtles exclaimed.

"Why only two of us?" Leonardo asked desperately.

"Because it will be easier for me if I only have two of you to watch." Master Splinter frowned. It was obvious that he wouldn't give them more than that. "The surface is a dangerous place, my sons."

"We know that," whispered a desperate Raphael. "We can take care of ourselves!"

"If you don't agree with it…" Master Splinter began.

"Of course we agree!" Donatello said quickly.

"In that case, I will let you decide who will come with me. We will do this tomorrow evening."


	9. Preparations

_Author's Note: So which turtles will be going? Let's find out…_

 **Chapter 8: Preparations**

The four future turtles were alone in the dojo. They couldn't believe what had just happened. Firstly they had been discovered by their past selves, which in itself was bad enough. Secondly their father had finally agreed to let them make a trip on the surface. His conditions were simple: he would accompany them no matter what and only two of the turtles were allowed to go.

Donatello began to talk hesitantly.

"Well, it could be worse…"

Raphael shook his head.

"Seriously, Master Splinter has trust issues. What does he think we will do?"

"Oh, I don't know," said Leonardo ironically, "the first time we went topside, we accidentally left a ninja throwing star with the emblem of our clan behind and it sent his worst enemy on our trail. Maybe he doesn't have trust issues; maybe he's just being realistic."

"Don't sell us short, Leo." Raphael looked exasperated. "Master Splinter doesn't know about that. And you know how far we have gone since that time. We are perfectly fit for a mission as simple as that!"

"Speaking of the mission, guys… Who is going to come with Splinter and me?" Donatello asked.

"With Splinter and you? So you are going no matter what, uh?" Raphael was fuming.

"Yeah, bro, what about us?" whined Michelangelo. "I can push buttons as good as you do!"

"You sure know how to push buttons, Mikey," Donatello mumbled. "The spying program I have in mind is easy to use if you are near the target. But last-minute adjustments may be required. I have to be there in person," he added louder.

"Guys, Donnie's right," interjected Leonardo. "He is one of the two."

The purple-clad turtle grinned smugly.

"Fine," groaned Raphael. "And who would be the second one? You, I suppose?"

"No, I think you should go," Leonardo answered as he looked his red-clad brother in the eye.

"Really?" Raphael sounded surprised.

"Really?" Michelangelo whined. "Why him and not me?"

Leonardo turned his attention to the orange-clad turtle and smiled fondly.

"Because Raph needs to unwind, or else he will explode and this lair will explode with him."

"You got that right, Leo." Raphael couldn't bring himself to really feel angry about this last statement. Partly because it was true, and partly because he was going to leave the lair. Finally!

"I need to unwind too!" Michelangelo protested halfhearted. He wouldn't win the argument against both Leonardo and Raphael. And it was true that Raphael was becoming more and more restless. The red-clad turtle could do more damage than Donatello's explosions when he was in this state of mind, and Michelangelo didn't want to be collateral damage.

"But you guys need to stay out of trouble." Leonardo was serious again. "You go near the TCRI building, Donnie hacks their security system and copies their files, you go back to the lair. Absolutely no fights." He looked at Raphael, who took his most innocent expression.

"Not my fault. The fights find me, not the other way around." Raphael grinned.

Leonardo rolled his eyes and sighed.

"And now that this is settled… What do we say to our younger selves?"

The rest of the evening went as quietly as it could as far as eight teenage mutant ninja turtles were concerned. The four older turtles were glad that they could at last speak and move normally around the lair. The four younger turtles were both curious and embarrassed about their other selves, and the general atmosphere was rather awkward. They were upset when they heard about Master Splinter's decision to go to the surface with the older Donatello and Raphael. Young Leonardo and Michelangelo were especially disappointed. They felt strangely sidelined because their older selves were stuck in the lair.

Master Splinter suggested that they got some rest and they went to bed early. The next day promised to be eventful.

On the following morning, the ninja master decided that he wanted to have a closer look at the future turtles' fighting skills and he asked them to join in with the younger turtles' training session.

"My sons, today we will use the presence of our four guests to train you to fight in unexpected situations." Master Splinter announced to the four younger turtles.

He turned to the older turtles.

"Each of you will choose his opponent. I will merely be watching your fight."

"Hai, sensei." The eight turtles answered, bowing.

"Donatello is first."

The older Donatello took a deep breath. He knew he had to be careful. He didn't want the younger Raphael to remember his so-called dream. _Plus I already beat him once,_ the genius turtle thought. _Now this is my chance to beat someone else… Someone who isn't as poor a loser as Raph._

"I choose Leo as my opponent," Donatello said calmly. The younger Leonardo grinned. The purple-clad turtle stole a glance at his own Leonardo, who was watching him with an amused look.

The two designated turtles stood and faced each other. Young Leonardo was trying to take this fight seriously, but he couldn't help feeling like it wouldn't be much of a challenge. _It's still Donnie we are talking about. How could he beat me?_ The blue-clad turtle thought arrogantly.

Two minutes later, he had to reconsider that statement. _I guess he could after all,_ the katana wielder grimaced. _I don't know how this could be more humiliating._ He was sprawled on the floor, his arms and legs were aching and his brothers had burst into laughter. Even Master Splinter was hiding a slight smile.

"Please, Donnie! Can you do that again? It was so much fun!" Young Michelangelo was laughing so hard tears were running down his cheeks.

Young Leonardo blushed and returned to his place.

"Donatello is the winner," announced Master Splinter. "Michelangelo, you are next."

The older Michelangelo took a few seconds to calm himself. _It is my turn to have fun,_ he thought. _And ohhh, I know exactly who will have the pleasure to be beaten by me! This is the chance of a lifetime!_

"I choose Raph!" The nunchucks wielder declared in a pompous tone.

The older Raphael frowned.

"Mikey," he whispered, "If you intend to use this occasion to humiliate me…"

"Of course not, brother mine!" Michelangelo whispered back, faking offense. "This is a fair fight, remember?"

With that, he advanced towards Young Raphael, who was looking at him with attention. The red-clad turtle didn't want to make a fool of himself like Leonardo had earlier. He wasn't going to underestimate his opponent.

The fight lasted a few minutes more than Donatello and Young Leonardo's had, but in the end, Michelangelo was the winner. He almost didn't rub it in, enjoying Young Raphael's defeated expression from his safe place behind his sensei. He had rushed here as soon as the fight had ended. He hadn't forgotten the first time his Raphael had been defeated by Leonardo. Saying that he hadn't taken it well was an understatement. _I will stay near sensei until Raph calms down,_ the satisfied orange-clad turtle thought. He looked at his own Raphael and shuddered. _Until both Raph calm down. But it was definitely worth it._

Master Splinter was enjoying himself immensely. _It will do Leonardo and Raphael good to lose to Donatello and Michelangelo for once,_ the rat master thought. He cleared his throat.

"Leonardo, it is your turn."

"I wish to fight Leo," the older Leonardo said impassively.

His brothers looked at him with surprise.

"Are you sure you can win this fight, Leo?" The older Raphael rolled his eyes.

The two blue-clad turtles raised and faced each other. Young Leonardo was perplexed, but determined to do his best. He didn't expect the fight to last very long. After all, he had just miserably lost to Donatello. How could he expect to win against his older and more experienced self?

To his surprise, he wasn't immediately sent to the ground. The older Leonardo seemed to content himself with blocking his strikes, moving through the entire dojo and forcing him to follow.

"Uh, Leo, what are you doing?" The older Michelangelo asked perplexed. "You know you're supposed to fight back, right?"

The older Leonardo smiled. "Not yet, Mikey. You don't get the opportunity to fight yourself every day, right? Let me enjoy it a while longer!"

He then began to attack, but his strikes were never powerful enough to actually defeat his opponent. The fight went on until Young Leonardo began to pant. He was at the limit of his stamina. The older katana wielder took it into account and sent him to the ground with a quick, precise kick. He bowed to his opponent on the ground and sat without a word next to his brothers.

"Okay, that was…weird." The older Raphael didn't know what to think. He tried to meet his brother's glance, but Leonardo wasn't looking at him.

Master Splinter was thinking deeply. It was obvious that this Leonardo could have ended the fight in seconds if he had wished to do so. Instead, he had forced his opponent to show the extent of his talent in both defense and attack. It hadn't escaped the ninja master's attention that the older Leonardo had been watching his opponent's moves with a special intensity, nodding unnoticed when he performed the right moves and frowning imperceptibly when he let himself open for an attack. _Like a teacher would,_ Master Splinter mused. He dismissed the thought. Leonardo was still too young to be in charge of training others. He addressed his last son.

"Raphael, it is your turn."

The red-clad turtle looked up and smiled.

"I choose Leo…"

Young Leonardo groaned. He felt exhausted.

"…and Donnie, Mikey, and Raph."

Muffled cries of surprise were heard through the dojo.

"My son, do you wish to fight all four of them?" Master Splinter raised his eyebrows.

"Hai, sensei." Raphael was rather pleased with himself. He was going to show these young turtles what a true fighter looked like.

"So be it, my son."

The four younger turtles stood. Young Michelangelo and Donatello had been happy to escape the duels so far. Young Leonardo was still breathing faster after his last fight. Young Raphael was looking at his older self with interest.

The older sai wielder wasn't worried. He could take them all, no problem at all. _They don't even know how to fight as a team yet,_ he thought. _If they try to attack me together, they will be in each other's way._

It turned out that the younger turtles didn't even try a coordinate attack. They just went after him one by one, and he defeated them one after the other in a single strike. Grinning smugly, he enjoyed the looks of awe they were giving him.

"Yame!" Master Splinter said. "Very impressive, Raphael. This training session is over. You are all dismissed."

The rat master looked at his eight sons leaving the dojo. The four younger turtles were surrounding the older Raphael, who was still grinning smugly. Young Raphael seemed to have forgotten his earlier defeat against the older Michelangelo, and the orange-clad turtle had left the protective side of his sensei. He was saying something about a video game competition. The older Donatello and Leonardo were already deep in a whispered conversation and Master Splinter supposed they wanted to prepare the surface mission.

 _They are stealthier. They fight better. It will be interesting to see how Raphael and Donatello react during our trip this evening,_ Master Splinter thought. _Not that I will let them out of my sight._


	10. Outside!

_**Chapter 9: Outside!**_

The older Raphael couldn't wait to go to the surface. Since he and his brothers had landed in the past, they had been grounded in the lair by their father. Now he was finally allowed to leave it. Even if it was for a quick spying mission, it still felt good. He felt sorry for Leonardo and Michelangelo, who would stay behind. _Master Splinter still doesn't trust us,_ Raphael thought bitterly. _I wonder what it will take for him to acknowledge our ability to take care of ourselves._

The older Donatello was ready to go. He and Leonardo had agreed on a simple plan. They would cover as much ground in the sewers as possible. They would exit them a few blocks from the TCRI building and use the rooftops to approach their target. Donatello's spying program would take a few minutes to break through the Kraang network. They would use stealth only and avoid engaging in a fight.

Master Splinter had stated that he would merely accompany Raphael and Donatello. The rat master didn't want to know about the details of the mission. He merely wanted to watch them and ensure they stayed safe. _Technically, it should be part of Leo's job,_ Donatello mused. He knew that it would be hard for the blue-clad turtle to stay behind. He would probably be worrying the entire time. _Luckily the T-phones are fully functional. I promised Leo we would call if we needed help. But the mission is simple, and Master Splinter will be with us. We will hardly be in any danger. Speaking of it, I wonder if sensei will really let us act without interfering._

The three participants to the mission were finally ready to go. The six turtles who would stay in the lair gathered to see them leave, wishing they could have come too.

The older Leonardo approached stealthily the shelves where Master Splinter kept his scrolls. He had pretended to go meditating in the dojo. Young Donatello was in his lab, Young Leonardo and both Michelangelo were competing in a video game and Young Raphael was feeding Spike in his room. He began searching the scrolls, looking for a particular one. He had just found it when his T-phone buzzed. It was a text from Raphael.

 _\- Master Splinter is driving me crazy._

Leonardo chuckled before answering.

 _\- More than me?_

 _\- Ahah, very funny. Actually, yes. At least YOU don't feel the need to hold my hand while crossing the street._

Leonardo stifled a laugh.

 _\- It could be worse. He could be carrying you._

 _\- Don't laugh. He is carrying Donnie across the rooftops right now, supposedly to allow him to focus on the map._

 _\- …You're kidding, right?_

 _\- I wish I was._

 _\- Take a few pictures. Please._

Leonardo shook his head, a wide smile on his lips. Maybe it wasn't such a bad thing that he wasn't participating to this trip. He took the scroll he had picked up and began to read it carefully. He suddenly felt a presence behind him and turned around.

"So it's your new way to meditate?"

His Michelangelo was watching him with a I-know-you-re-up-to-something-and-I-want-to-know-what smile. Leonardo sighed inwardly.

"I thought you were in a video game competition," he answered matter-of-factly.

"It's not my turn, and I was wondering what you were doing. Is this one of Master Splinter's forbidden scrolls?"

"Technically, our Master Splinter allowed me to read some of them."

Leonardo felt sheepish. It was the truth, but his father had insisted that he would always do it under his guidance. The mantras written on the scrolls could be dangerous. Michelangelo didn't seem to be fooled.

"Sure, Leo. This must be why you waited until everyone was busy elsewhere and Master Splinter was out of the lair. Because you're totally allowed to read them," the orange-clad turtle answered wryly.

Leonardo sighed. Michelangelo wouldn't be deterred so easily. He knew that trying to lie to his orange-clad brother would only get him in trouble. He didn't want to be at the receiving end of one of Michelangelo's famous revenge pranks.

"This one has a mantra about memory. I am not exactly sure what it does and I am trying to determine if it could be useful."

"Why?" Michelangelo sounded confused. "Do you have memory problems?"

"No, I seek a way to erase our younger selves memories of what happened here before we come back to our time."

"Uh. A mantra could do that?"

"Yes. I just don't know if _this_ mantra could."

"Can't you ask for Master Splinter's help?"

Leonardo sighed. He didn't want to involve his sensei just yet.

"Maybe later. Can I trust you to hold your tongue?"

Michelangelo smiled happily.

"Of course, no problem! You know me, I can totally keep secrets!"

Leonardo ground his teeth. _Sure you do, Mikey. Until you spill them out at the worst possible time._ However, he had no other choice than to trust his brother. He put the scroll away and took a closer look at Michelangelo. His brother seemed less happy than usual. He was probably still annoyed with having to stay in the lair while Donatello and Raphael were on the surface with Master Splinter.

"You know, Mikey," Leonardo began slowly, "I was thinking about how unfair it was that we couldn't participate in this epic water balloon fight yesterday. Maybe we could fix that now, and show our younger selves a thing or too."

He was rewarded with Michelangelo's huge smile.

"Dude, what are we waiting for? Let's take those turtles down!"

On the surface, Master Splinter had finally come to his senses. He had almost panicked at the beginning. Seeing his precious sons so close to the humans who would hurt them if they knew of their existence had triggered his most protective instincts. He hadn't meant to hold Raphael's hand or to carry an embarrassed Donatello across the rooftops. It had just happened. He took a deep breath. He knew he couldn't continue hurting his sons' pride this way. He had to learn to let them go.

They had arrived at the right building. Donatello was focused on his T-phone. Raphael was surveying the area. Master Splinter was tense, but his sons seemed to have the situation well in hand.

Raphael was relieved that his father had finally decided they were able to move by themselves. He watched the city. He had missed the sight. He couldn't help missing Leonardo and Michelangelo's presence, too. He sent another text to Leonardo.

 _\- We are at the TCRI building. Now Donnie is trying to explain to Master Splinter how his spying program works. It's boring. How is your night?_

 _\- Refreshing. Uh, can you give me a warning when you will be ready to go back to the lair?_

Raphael wondered what his brothers could possibly be doing. He texted Michelangelo next.

 _\- It's a pity you're missing all the fun. I hope Leo isn't too worried about us._

 _\- Nope, I'm helping him chill out. And I'm helping you cool down, too. Look!_

Raphael's suspicions were growing. He groaned when his brother sent him a picture of his younger self, his pet turtle Spike on his shoulder and a wilted leaf in the hand, trickling with water. You could almost see a cloud of hot vapor around him.

 _\- You better run fast._

 _\- I'm on it!_

"Raphael?"

The red-clad turtle turned around to face his father.

"Sensei?"

"What are you doing?"

"Uh, I was checking on my other brothers. You know, so they don't feel too left out."

Raphael's tone was slightly accusatory. Master Splinter sighed. At this moment, two things happened simultaneously.

On one hand, Donatello exclaimed that he was done.

On the other hand, a Kraang surveillance droid appeared on their side of the building and biped.

"The system that is the security system of Kraang has been what is called hacked by beings that are not allowed beings that are allowed to do what is called hack the system that is the security system of Kraang. Kraang must now perform what is known as an investigation."

Master Splinter froze. He recognized the being. It looked like one of those who had hunted him and his baby sons down after their mutation all these years ago. He forced himself to remain calm. _How are my sons involved in this business? These beings are even more dangerous than the humans! This is really irresponsible!_

He heard a whistle and watched as one of Raphael's sai flew past him and hit the droid, sending him crashing in the street above them. Raphael had a wide grin.

"Finally, we got some action!"

Donatello jumped down the building and retrieved Raphael's sai, sending it back to its owner. He took something else within the droid.

"This should prove useful," the purple-clad turtle said. "Do you think there are more of them?"

Master Splinter looked at his son in disbelief. Donatello seemed so calm, as if this was an average evening trip.

"My sons, what have you done? Now they will chase us! We have to get out of here!"

The three of them used the nearest manhole to disappear in the sewers. Raphael texted Leonardo to let him know they were coming back. He left out the details. He was feeling unsure. Had he acted too rashly by hitting the droid instead of merely disappearing in the shadows? He looked at his sensei. Master Splinter seemed distressed.

As soon as they reached the lair, the six turtles who hadn't come out encircled them and questions burst out.

"No one is allowed to leave the lair until further notice. I need to meditate. Do not disturb me," Master Splinter stated calmly before heading for the dojo.

"What happened?" A worried older Leonardo asked, hiding a suspicious mop behind his back.

"Good news is, we got the data. Bad news is, I don't think sensei appreciated our encounter with a Kraang droid," Donatello said sadly.

"What is a Kraang droid?" Young Michelangelo asked.

"It's an evil robot belonging to a bad chest brain thingy," the older Michelangelo explained.

Young Michelangelo nodded as if this answer made perfect sense. On the contrary, Young Donatello, Leonardo and Raphael wore nonplussed expressions.

The older Leonardo sighed. It seemed that his brothers had managed to draw the unwanted attention of the Kraang. He had a feeling Master Splinter wasn't going to let any of them leave the sewers again any time soon.


	11. Misconceptions

**Chapter 10: Misconceptions**

Master Splinter had been deeply disturbed by the whole Kraang business. The future turtles hadn't dared to ask him if the four of them could go out together when he had finished his post-mission meditation the day before. The older Raphael and Leonardo were currently in the dojo trying to convince him, with little success.

When the older Raphael and Donatello had summarized the events of the mission, Young Raphael had been especially proud of his older self and therefore of himself. Since then, he had been mercilessly teasing Young Leonardo about it.

"Hey Leo! You see? Future Me has been outside, destroying evil alien robots, while Future You was grounded in the lair! What can I say? Some of us are just way better than the others!"

"Come on, Raph," Young Leonardo protested. "Master Splinter had decided that only two of them would go and…"

"And he took only the best with him!" Young Raphael interrupted him bluntly.

Young Donatello smiled. His future self had been one of the two. He had been an important part of the mission. Right now, he was in the lab analyzing data with the older Michelangelo, who was supposedly helping. _More probably, he's bothering him,_ thought the purple-clad turtle. Nevertheless, it felt nice to know that in the future, his brothers would need his skills so badly. Young Leonardo noticed his smile and groaned.

"Oh come on, Donnie! Do you actually agree with Raph?"

"Uh, you know… Don't take it wrong, but it just looks like Mikey and you weren't just as important as Raph and I this time. No offense there!" The purple-clad turtle answered quite smugly.

Young Michelangelo was steering clear of the argument. He had actually enjoyed the time he had spent with his brothers and the older Michelangelo and Leonardo. He almost wanted to remind his proud brothers that all of them had stayed in the lair yesterday, but thought better of it.

"Don't worry, Leo," Young Raphael went on. "We can't all be mighty heroes. Maybe a boring life suits you better!"

"My life is not boring!" Young Leonardo protested.

"Yes it is! Future You obeyed Master Splinter's orders to the letter, like you always do too…"

"And it is only appropriate!"

"… and he stayed in the lair like a good little soldier. I'm just saying, it's bo-ring!"

Young Leonardo had had enough of it. He tried to find something striking to say, but nothing came to his mind.

"Whatever. I'll be in the sewers," the blue-clad turtle mumbled instead before storming off. Young Raphael watched him go with a smug smile.

A few minutes later, the older Leonardo and Raphael exited the dojo. Raphael looked exasperated and Leonardo had a tired look. Obviously, Master Splinter wouldn't budge.

"Where is Leo?" Leonardo asked. He had a bad feeling about his younger self.

"I don't know, he just left." Young Raphael shrugged. "I guess he couldn't stand the truth."

The older Raphael exchanged a glance with his Leonardo.

"What do you mean?"

Young Raphael looked defiantly at them and didn't answer. Young Michelangelo decided he had been silent long enough.

"Raph here was telling him how boring he was. He was boasting because you," he pointed his finger at the older Raphael, "had a wonderful adventure while you," he indicated the older Leonardo, "obediently stayed behind."

"Tattle-tale," Young Raphael whispered. His older self looked strangely disappointed and he felt embarrassed.

Leonardo narrowed his eyes.

"I will go after him. Just in case he does something stupid."

"Like you would ever do such a thing," mumbled Young Raphael.

The blue-clad turtle just gazed at him and Young Raphael had to look away. Then Leonardo disappeared in the sewers.

The older Leonardo felt worried. He knew his younger self had probably been hurt by Raphael's words much deeper than the red-clad turtle had intended. He found him a few tunnels away, hesitating under a manhole cover.

"Does it really matter to you?" The older Leonardo said softly.

Young Leonardo jumped.

"What?"

"What Raphael said," his older self went on. "Does it matter to you to the point that you would endanger yourself in such a way?"

"I…I…" Young Leonardo stumbled. "I guess it does." He wasn't looking at his older self.

"I know Raph has a way to irritate people at times…"

"He's insufferable!"

"…but is he really the reason why you're about to do one of the biggest mistakes of your life?"

"And why would you care?" Young Leonardo turned to face his older self. _Raph was right about one thing. You seemed quite happy to stay in the lair yesterday,_ he thought bitterly. "Maybe I just need to do this. Maybe I just need to go to the surface on my own to prove him he's wrong!"

The future Leonardo tilted his head.

"You're not ready to leave the sewers yet." He was talking in a reasonable, no-nonsense voice.

"And when will I be ready?" Young Leonardo exploded. "Seems to me that _you_ still aren't ready!"

 _There we are,_ the older Leonardo thought. His next question was almost a whisper.

"Are you mad at Raph or are you mad at me?"

Young Leonardo bit his lip. He hadn't meant to say that, but he was boiling inside. His future self wasn't at all what he had been dreaming. He had been dreaming of crazy adventures, of heroes saving the world. Participating in a water balloon fight or meditating for hours hardly qualified for it in the eyes of the young turtle. But he had no right to resent the older turtle. He looked at the manhole cover. _I could leave the sewers now, I could prove Raph and my older self that I can be bold and daring too… And then what? Master Splinter would be furious. And disappointed, which would be worse. And what if something happens when I am outside?_ He breathed out and slowly released the tension. He couldn't bring himself to do it, now that his anger was already calming down.

"I'm sorry. I'm just frustrated, I guess. The situation is quite…difficult. Seeing you guys around, from the future and all, and you won't even tell us how it is like." He shrugged.

"I know. It's difficult for me too." The older Leonardo smiled. "For the record, I don't think you're boring. And Raph doesn't think it, either." He let out a small laugh. "At least not the whole time."

At that, Young Leonardo had to smile too.

At the lair, Young Raphael was feeling the disapproving looks of his siblings.

"What?" The red-clad turtle finally said. Young Michelangelo shook his head.

"It was pretty mean to tell Leo that he's boring just because he's more obedient than you. You hurt his feelings, bro."

"I don't care," Raphael lied outright. "I don't know why he's so touchy today. That's just lame!"

"Fine, think about it your way," Young Michelangelo shrugged and left to check on his older self.

Young Donatello followed him, curious to see what the older Donatello had discovered.

The two Raphael stayed alone in the living room. The older Raphael had mixed feelings. He knew that his younger self had meant no harm. On the other hand, Raphael was mad at him for being so oblivious. Young Raphael seemed to feel his disapproval and he felt the need to explain himself.

"Maybe I went too far. But I didn't think Leo would lose his temper and just storm off. He never does anything stupid."

 _Don't take him for granted,_ the older Raphael wanted to say. _Don't take any of them for granted. Leo needs your support and you need him too._ He closed his eyes briefly. Flickering memories went through his head. Leonardo staying behind in a sinking Kraang ship. A shattered window, a tattered body. A bathtub, weeks of hope and uncertainty… But he couldn't tell his younger self any of it.

"Never mind. He will forgive you." He simply answered.

At that moment, both Leonardo jumped the turnstiles at the entrance of the lair.

"I'm going to ask Donnie if he has made some progress," the older Leonardo said.

The older Raphael nodded and followed him to the lab, leaving the two younger turtles alone.

Donatello's lab was now crowded with six turtles, four perplexed, one attentive and one trying to explain some very scientific stuff.

The future Leonardo interrupted his genius brother's technical explanations.

"What are you saying, exactly?"

"The Kraang have indeed a research project about controlling time and space," the future Donatello answered. "But it is not advanced enough to actually enable them to time-travel. In fact, they are abandoning it and will soon dismantle the equipment." He hesitated. "The pieces I used to create my device were part of that equipment. There is a possibility that they traced their way back to the time when the equipment was last in use – that is, here and now. He locked his eyes with his blue-banded brother. "To check that and reverse the process, I need to check the equipment in person."

Leonardo grimaced.

"You mean that we have to infiltrate TCRI… again."

"Yes." Donatello said matter-of-factly.

Raphael grunted.

"Sensei will be thrilled."

Young Donatello had followed the entire conversation with the utmost interest. He couldn't wait to discuss this further with his older self. It felt so nice to have someone who could actually understand science for a change.

They exited the lab together. In the living room, Young Leonardo and Young Raphael were discussing quietly. They both looked relaxed.

"So did you two make amends?" Young Michelangelo asked happily.

"Yes," Young Leonardo chuckled.

Young Raphael crossed his arms but didn't deny it.

"Good," the older Raphael said with relief. "And you know? About Leo never doing stupid things?" He winked at his younger self. "Just wait until he meets Kar…"

" _Raph!_ " The older Leonardo shouted.

Young Michelangelo frowned. The light was dim, but he could have sworn Leonardo was blushing.


	12. Another Chance

**Chapter 11: Another Chance**

The older Raphael stood in the center of the dojo. His brothers and the four younger turtles sat on the floor. Master Splinter was looking at him sternly. Yes, Raphael was in trouble.

It was all Michelangelo's fault.

The red-clad turtle thought with irritation at what had happened earlier. Michelangelo had been getting on his nerves for a reason he couldn't even remember now. He had already been exasperated by Master Splinter's consistent refusal to allow them to go back to TCRI. When Raphael had finally had enough of his orange-clad brother's antics, he had responded to it with violence.

The problem was that he had been persuaded at the time that it was his Michelangelo. _How could I have known that it was in fact Young Mikey?_ Raphael thought. _He was acting and speaking exactly like my Mikey, purely and simply because my stupid brother thought that it would be fun to exchange places with his younger self for the day. It was supposedly to see if we could see the difference! Well, I couldn't!_ This fact was embarrassing enough. But when the older Raphael had retaliated, he had done so with too much strength and speed for the younger Michelangelo to properly protect himself. _I didn't mean to hurt him, really. My Mikey could have avoided th_ _at_ _blow easily!_

He had tried to explain that to Master Splinter, but the rat master hadn't believed it. It hadn't helped that the older Michelangelo hadn't backed up his story. _How could he?_ Raphael fumed. _He just dragged me down!_

Now the older Raphael was facing his sensei. Young Michelangelo was looking at him with a hurt expression, clutching his aching stomach. Young Donatello and Leonardo had disapproving expressions. Young Raphael wasn't looking at him. His younger self probably believed his story, but he couldn't forget so easily that Michelangelo was hurting. The older Raphael turned to look at his own brothers. Michelangelo's expression was shouting _Serves you right!_ Leonardo and Donatello were calmly waiting for Master Splinter's speech. They didn't have to wait for long.

"My son, it is dishonorable to use your superior strength against someone who cannot defend himself properly. You are far more experienced that Michelangelo here…"

"I didn't know it was him!" The older Raphael tried again.

"Silence!" Master Splinter inhaled deeply. "I hope you will understand how wrong it was after this fight."

The red-clad turtle grimaced. So his father wanted to fight him. Well, maybe fight wasn't exactly the right word for it. Maybe mop the floor with him was a more accurate description of Raphael's future situation. And both his brothers and their younger selves would witness it. _Enjoy it, probably,_ Raphael thought bitterly.

"Always choose the side of right, my sons." Master Splinter was going on with his lesson.

 _It wasn't my fault. It is so unfair!_ Raphael was desperate. There was no way he could escape his fate. _I won't even last two seconds. I wonder if he will make me stand against him more than once,_ he thought glumly.

The older Leonardo was outwardly extremely calm. However, his mind was in turmoil. _As if we needed that on top of the rest. If only Raph had stayed calm. If only Mikey had found another prank. If only Father had allowed us to leave…_ The blue-clad turtle took a deep breath. What had happened, had happened. There was no use in brooding over the past. Now he had to act upon the present situation.

The blue-clad turtle of the future glanced at his Raphael, then at his father, then at his Michelangelo. He hung his head and clenched his fists. This was going to hurt.

Then he stood and placed himself by Raphael's side.

Everyone else in the room looked at him like he had lost his head. _Which I probably have,_ Leonardo thought wryly _._ Master Splinter talked to his son calmly.

"Leonardo. What are you doing?"

"Choosing the side of right, sensei. I believe that Raphael has been unfairly accused."

The red-clad turtle had recovered of his surprise. He hid his happiness at this statement and answered casually.

"It's about time someone figures that out."

Master Splinter furrowed his brow.

"If that is so, you will share Raphael's fate," the ninja master said.

Leonardo hesitated. He could stop there and allow Raphael and himself to be beaten into the ground by their sensei because of something their Michelangelo had largely contributed to create. There was no doubt Raphael would retaliate later and the situation was doomed to escalate again. Or he could ensure that this whole affair would strengthen their ties as a team. He had carefully avoided acting openly as a leader until then.

 _Maybe it's time to reconsider this choice,_ the katana wielder thought. Having made his decision, he motioned for his two remaining brothers to join them. The gesture was subtle but imperative. It belonged to their hand-signals code.

The older Donatello sighed. The older Michelangelo was about to protest, but thought better of it. After all, it was partially his fault. Both of them stood and joined Leonardo and Raphael.

"Now that's the spirit," Raphael said fiercely while looking at his orange-clad brother.

The nunchucks wielder shrugged and smiled at him quite sheepishly.

Master Splinter was now flabbergasted. What was happening here?

"You know this is going to hurt, right?" The older Donatello said matter-of-factly.

"It can't be worse than the first time we faced the Sh…" The older Michelangelo startled when Leonardo elbowed him. The blue-clad turtle glared at his brother. Mentioning the Shredder at this time and place was probably the worst idea ever. "The Shocking Pizza Thief of the Sewers," Michelangelo went on. To his credit, he almost didn't stammer.

Master Splinter blinked at him. The four younger turtles were watching the scene in amazement.

The older Raphael felt a lot better with his brothers by his side. There was something extremely comforting in not being the only one to take the blame.

The older Leonardo's eyes were set on Master Splinter. The blue-clad turtle was waiting for his sensei's reaction.

"Hmm," Master Splinter just said. Then he moved and got ready to send each of his future sons to the ground. _Thwack._ One down. _Thwack._ Two. _Thwack._ Three. _Th_ … Master Splinter's eyes widened. Leonardo had just managed to dodge his blow. For a second, their eyes met. Then the ninja master increased his speed. _Thwack._ Four turtles to the ground.

Master Splinter waited a few seconds before speaking in a calm voice.

"Leonardo, I wish to speak with you."

The older Leonardo stood and followed his father out of the dojo. His three brothers were still sprawled on the floor and gave no indication that they intended to stand ever again. The four younger turtles were open-mouthed.

"What the heck just happened?" Young Raphael exclaimed.

"It's called team work, bro," the older Michelangelo answered. His voice came out muffled by the fact his face was kissing the floor. "It's amazing!"

In Master Splinter's quarters, Leonardo was kneeling in front of his father, head bowed.

"My son. Why did you act in such a way?" Master Splinter asked quietly.

"Sensei…" There was so much Leonardo wanted to say. So much that he couldn't. He looked up at his beloved father.

"We are a team. We stand together. We win together… and sometimes we lose together, too." _Like you taught us to,_ he silently added _._

Master Splinter was looking at him, thinking about his earlier behavior. He was trying to figure out what he had seen in his son's eyes during the fight.

"Fine," he finally said. "If that is so…" The rat master closed his eyes and forced himself to go on. "I will allow you and your brothers to carry out your mission."


	13. Look At Me

**Chapter 12: Look At Me**

The four future turtles were getting ready for their mission. They had welcomed the news that Master Splinter had finally allowed it. Donatello was performing a last-minute calculation. Michelangelo and Raphael were checking their weapons. Leonardo was talking with Master Splinter.

The ninja master had given them strict orders not to engage the Kraang in a full-scale fight. If they were discovered, they would have to turn back immediately. It was obvious that Master Splinter was anxious. In fact, he was so anxious that he had insisted to remain in contact with them the whole time. The four older turtles hadn't complained. As Raphael stated it, it was already a miracle that he was letting them go on their own. Therefore Donatello had linked his T-phone to Young Donatello's computer. That way, the rat master would be able to follow his sons' progress from afar. He would hear and see what the T-phone heard and saw. As said T-phone would probably stay at Donatello's belt, it would mostly display the purple-clad turtle shell, but Master Splinter wanted to leave nothing to chance. You never knew what could happen.

The younger turtles were watching the preparations with envy. They were not only confined in the lair but they were also forbidden to watch their future selves like Master Splinter would.

Using his knowledge of the Kraang, Donatello had been able to locate the lab where the alien robots had conducted their experiments on time and space. As they were about to dismantle the equipment, no scientists were working in the lab at the moment. It made the turtles' task easier.

The four turtles were finally ready to depart. They met Master Splinter and their younger selves at the turnstiles. Master Splinter flooded them with advice, his last one including filthy human bathrooms. His older sons endured it with good grace and a sense of déjà vu and then quickly left before he could change his mind.

Master Splinter sighed and made for Young Donatello's lab, where he locked himself up. The four younger turtles remained in the living room, glancing disillusioned at each other.

"I feel left out," Young Michelangelo whined.

"Me too," Young Leonardo shrugged. "I don't even understand what made Master Splinter change his mind. He was so adamant that they couldn't carry out this mission."

"Your guess is as good as mine," Young Raphael added. "Especially after witnessing the way he beat them this morning."

"I think we missed something," Young Michelangelo said.

"You do that all the time," Young Raphael smirked.

"But this time we all did!" Young Michelangelo protested. "Even Donnie… Donnie?"

Their purple-clad brother had been trying to discreetly leave for his room. He turned around and answered sheepishly.

"Yes?"

"Donnie, what are you doing?" Young Leonardo sounded suspicious.

"Uh… You know, it has been an exhausting day. I think I need some rest. See you!"

Before Young Donatello could safely disappear into his bedroom however, Young Raphael reached for him and immobilized him.

"And we believe that you are not telling us everything," the red-clad turtle said menacingly.

Young Donatello gulped. He looked at his three rightly suspicious brothers and surrendered.

"Fine. If you must know, and apparently, you must…" He glared at Raphael who was still holding him. His brother just smiled back. "…I kind of have changed the settings of my lab computer so that every bit of data it receives will also be sent through our lair wires and…"

He bit his lower lip. "You know I have recently installed a TV and speakers in my room."

"Yes, we were wondering why," Young Leonardo answered. "You spend your entire free time either in your lab or with us. Why would you need a TV in your bedroom?"

"Because that way," Young Donatello said deliberately slowly, "I won't have to be in my lab to watch what my lab computer will display in, let's say, the next few hours."

The purple-clad turtle could tell the exact moment each of his brothers finally understood.

"That way…" Young Raphael began excitedly.

"…we can spy on our older selves without Master Splinter's knowledge!" Young Leonardo went on.

"We can?" Young Michelangelo said. "I mean, of course we can! But won't Master Splinter be mad?"

"We won't tell him," Raphael snorted.

"It is only appropriate," Young Leonardo stated. "After all, they did spy on _us_ for almost a week!"

"Follow me, then," Young Donatello concluded with a satisfied smile before leading them all to his bedroom.

The four future turtles were running on the rooftops of the city. They were well aware of the fact that Master Splinter was watching them and thus avoided talking. They didn't need to anyway. They had rehearsed the plan at the lair and they could communicate with hand signals.

Soon, they arrived at the TCRI building. This time, Donatello scanned the area for Kraang droids before nodding to Leonardo that everything was all right. The four turtles entered the building and made for the deserted lab room, using their stealth skills and their experience of the place to remain undetected. Inside the Kraang lab, Donatello began to study the ready-to-be-dismantled equipment while Michelangelo watched him, Raphael watched Michelangelo and Leonardo watched the door.

"Oh, no."

Donatello's statement, the first words any of the four future turtles had spoken so far, made his brothers turn around in alarm.

"Leo, look at this."

Leonardo signaled to Raphael to take his place at the door and he advanced towards the screen Donatello was pointing. He looked at his genius brother quizzically.

"Yes? Donnie, I do not speak a very fluent Kraang."

Donatello didn't even glare at him, which proved how upset he was.

"I found out why my device didn't work. I can use a piece of this equipment here," he took a small antenna which was glowing with a pink light, "and use it to send us back to our present."

"Which is good news, right?" Michelangelo said.

"Yes, but I also found out what the Kraang will do to replace this failed project. Guys, we have to stop them!"

"Dude, are you sure it's a good idea? Aren't you the one who said that we should avoid disturbing the past at all costs?"

"We won't have a future if the Kraang succeed, Mikey!" Donatello sounded desperate.

Leonardo looked at him. He knew that if Donatello said so, it was true. It meant that they had to do something. Something that most probably involved engaging in a full-scale fight with the Kraang.

"How long do we have?" The blue-clad leader asked simply.

"Thirty minutes," Donatello responded.

Leonardo shook his head. _I knew it was going too smoothly._ He looked at his three brothers in turn. Raphael looked eager to confront someone or something. Michelangelo's expression was focused and serious despite his eyes' twinkling. Donatello was waiting for him to say something else. Leonardo took a deep breath. _So be it._

He took Donatello's T-phone and switched it off. Then he smiled at his three brothers.

"Gentlemen, let's save the world…again."

Back at the lair, Master Splinter was frowning. He had been hanging onto his sons' every word when the speaker had become silent. Maybe there was some sort of technical problem?

He exited Young Donatello's lab and searched for his genius son. He didn't have to go far. He could have heard the shouts coming from his son's bedroom from a mile away. He sneaked into the room.

"My sons, what is the matter?"

Four guilty turtles jumped.

"Uh…"

The rat master looked at them and frowned.

"Have you four been spying on?"

They didn't answer. Master Splinter decided that he would deal with them later.

"Donatello, I believe that there is a problem with your speaker. It doesn't work anymore."

Young Donatello tilted his head.

"Uh, sensei… I don't think there is a problem with the speaker. I think they just…kind of… switched the phone off?"

" _What?"_ Master Splinter shouted. His four sons shrank.

"But…" Young Donatello added quickly. "I may have an idea. You see, there are security cameras in that building. My older self has probably disabled them, but maybe I can hack his software and…"

"Sure thing, Donnie. Hack yourself all you want," Raphael muttered.

The purple-clad turtle ran to his lab and began working frenetically on his computer. His father and brothers had followed him. He looked back at them. They were only inches from his shell.

"It will take some time… I could focus better if you allowed me to breathe," he said with irritation.

The four mutants stepped back sheepishly.

Twenty minutes later, the tension was tangible in the lair. Master Splinter was overwhelmed with worry and fury. What were his future sons thinking? If they had switched the phone off on purpose, it certainly meant that they intended to do something he would disapprove of. Master Splinter closed his eyes. _I should never have let them go…_

Suddenly, Young Donatello exclaimed.

"I did it! I couldn't hack every camera – my older self is too clever for that," Young Donatello smiled smugly despite the severity of the situation," but I can trace their thermal signature to a room where one camera hasn't been updated properly and… here it is!"

He hit one last button with a proud expression and a blurred image formed on the screen. An image that the five mutants watched in disbelief.

There was no sound, which made the scene more unreal. They could make out the four future turtles fighting against an army of alien robots.

Master Splinter had a lump in his throat. His sons, his four beloved sons… they were beautiful. Each of them was moving with a grace the ninja master had never seen them display before. They fought with deadly accuracy and strength. What was more, they fought _together_. Their weapons and bodies mingled with the speed of their moves. Katana, sai, bo staff, nunchucks were flying in the air in perfect harmony. He saw color trails of blue, red, purple and orange.

Then he saw only smoke, and the screen went black.

Master Splinter blinked. If there were tears in his eyes, his younger sons didn't notice them. They were still looking at the black screen in awe.

Young Raphael spoke first.

"Guys… I think we can rightfully say that we are amazing."

"Did you see me? Did you?" Young Michelangelo chirped.

"But what happened?" Young Leonardo asked.

Those words broke Young Donatello's trance. He ran to the living room and turned the TV on. He switched to their favorite news channel. A reporter was showing images of the TCRI building surrounded by smoke.

"… been an explosion… We don't know yet what happened… The police are arriving at the scene right now…"

 _Explosion?_ Master Splinter thought. He felt numb.

"Wh…what?" Young Michelangelo asked. "Do you think we just…"

"No way!" Young Leonardo answered fiercely.

Then they heard static from Young Donatello's speaker in the lab, and an unmistakable voice spoke.

"Hello?"

It was the older Leonardo's voice.

"Sensei…I… I know you can't answer back, and I know you're probably worrying right now, and by the way, sorry for switching the phone off… but we are all fine, I promise."

Relief overwhelmed the ninja master. And then anger. He closed his eyes. So it had been Leonardo's decision? He was so going to get back at him for that.

"We will be coming back as soon as possible…"

Another voice was heard. A very happy one.

"As soon as we finish this delicious roof pizza! My favorite!"

"Which pizza isn't your favorite, Mikey?" Another voice grunted.

"You better hurry, Leo, or you won't have any!"

"…as I said, as soon as possible."

And the speaker was mute again. Master Splinter turned to look at his present sons. He needed to calm down. Of course, he could have meditated while waiting for his future sons' return, but he had unfinished business to attend to.

"And now… didn't I forbid you to watch your future selves?

"Guys, before we meet our ultimate doom, I want to say I told you so," Young Michelangelo said matter-of-factly.


	14. See You Later

_Author's Note: Almost there! Next chapter will be the epilogue. Thanks for your kind reviews! I am so happy to read them._

 **Chapter 13: See You Later**

When the future turtles arrived at the lair, they discovered their younger selves lying exhausted on the couch. Young Michelangelo gathered his remaining strength to feebly raise his arm in a welcoming salute.

"Guys," he croaked, "you were awesome!"

"Uh," the older Donatello answered, "what happened here? It looks like you went through a harder time than we did."

"Hmm…" Young Donatello blushed. "Maybe Master Splinter was mad at us for…uh… spying on you?"

The older Leonardo rolled his eyes. He wasn't really surprised at the statement. In fact, he had anticipated it. It was one of the reasons why he had switched off Donatello's T-phone, preventing Master Splinter and their younger selves from hearing them. What he hadn't anticipated was Young Michelangelo's comment. Why did he think they were awesome?

His fears were confirmed by Young Raphael.

"Yeah, that was some fighting!" The red-clad turtle said in a weak and happy voice.

The older Michelangelo beamed.

"Dudes! Did you really see us? When we infiltrated the Kraang headquarters and defused the explosive and messed with the Kraang minions and blowed up the portal and jumped from the last floor and saved the stray cat?"

The younger turtles looked at each other in astonishment. Young Leonardo answered in a shocked voice.

"In fact, we just saw you fighting robot aliens. For thirty seconds or so."

The older Raphael smacked his Michelangelo.

"What did we say about this big mouth of yours?"

The older Michelangelo's response was lost when a voice suddenly echoed through the living room.

"My sons. I am glad that you are home."

The four older turtles immediately turned to face their father. The tall rat's face was unreadable. The older Donatello coughed.

"I think I will begin my calibrations immediately."

"I'll help!" The older Michelangelo offered.

Both of them disappeared quickly into Donatello's lab.

"How was your mission?" Master Splinter asked calmly.

The older Leonardo avoided meeting his piercing eyes.

"Uh, it was a success. We were able to retrieve what we needed despite an unexpected turn of events…"

He turned to his only remaining brother, silently pleading him to help. Raphael took the hint and to his credit, he really tried.

"Yes, the situation was fully under control…"

Master Splinter was fighting to keep his composure. He advanced towards his apprehensive sons and bent to study their faces.

"And how is an explosion big enough to attract reporters _fully under control_?"

The older Raphael held back a curse. Maybe it hadn't been the most sensible thing to say.

Leonardo bit his tongue. The recent events had been exhausting for the blue-clad leader and even if the roof pizza had helped release his stress, he was still on edge. _There is no appropriate answer to that question,_ he sadly acknowledged. _At least, not one that would keep us from trouble._ He went for a non-answer.

"We are all fine and we have what we needed. The humans didn't see us and the Kraang will be too busy to hunt us -you- down for a long time."

He took a deep breath and bowed low.

"I am sorry that we didn't respect your orders, but the situation called for desperate measures."

Master Splinter was watching him quietly. He took a look at the four younger turtles who were pretending not to be listening at the argument, and failing miserably. He sighed.

"I will ponder this," the ninja master finally said.

The relief on the older Leonardo and Raphael's faces was so obvious he had to repress a chuckle. His feelings were so confused it almost hurt. _They are fine. They stayed alive. But it was so ridiculously dangerous…_ He mused. _But again, their fighting was impressive. And it looked like they were used to this…_ Master Splinter closed his eyes and refused to let himself be scared by the implications of this particular fact.

"I believe we all need some rest," the rat master concluded. "We will talk more in the morning. Make sure your brother doesn't spend the rest of the night working."

"Hai, sensei," the future Leonardo and Raphael answered.

Young Raphael groaned.

"Rest sounds fine by me."

Master Splinter left the room and the older Raphael smiled at his Leonardo.

"Come on, Leo. Let's check on the two cowards who let us take the heat."

The next morning, none of the eight turtles was up early. Master Splinter savored every second of silence in the lair. He decided to initiate a task he had postponed for too long: classifying his scrolls. He was in the middle of it when he began to hear noises in the kitchen. His sons were finally waking up. He was about to finish when the older Michelangelo entered the dojo, speaking.

"Hey Leo, I heard the scrolls. Did you finally talk to Master Splinter about…"

The orange-clad turtle suddenly saw who was there and interrupted himself abruptly.

"Oops. Uh, never mind, sensei. I think you were someone else… I guess I'm still half-asleep…" The short turtle retreated carefully. "Don't mind me!"

Master Splinter coughed.

"Michelangelo? What was that all about? Why would you think Leonardo was here?"

The orange-clad turtle laughed self-consciously.

"No reason, sensei! Just… goofing around, that's all!"

The poor turtle could feel his insides melt under his father's gaze. _Sorry, Leo. I don't think he bought it. You're on your own this time,_ he thought sheepishly.

A few seconds later, Master Splinter's angry voice could be heard through the entire lair.

" _Leonardo!"_

In the kitchen, both Leonardo jumped. Young Leonardo tilted his head and talked to his older self.

"I didn't do anything! Did you?"

The older Leonardo stood up.

"Uh… I think we can reasonably suppose it's for me, then. Guys, if I don't make it through, give me a nice elegy."

"He who was stupid enough to anger a ninja master, may he rest in peace," the older Raphael offered helpfully.

His Leonardo rolled his eyes and smiled before leaving the room. The other turtles chuckled.

"Seriously, though," the older Donatello asked in a curious tone. "What do you think he did?"

The older Michelangelo chose that moment to enter the kitchen in a very guilty-looking manner. His voice didn't ring true when he asked,

"So, what's the schedule today? Donnie, do you need any help with your science?"

His purple-clad brother looked at him suspiciously.

"No, I am ready. The only problem that remains is our memories. We can't leave this time and let our younger selves remember what happened, it could prove disastrous for our present…"

The older Michelangelo fidgeted.

"Uh, maybe I have just helped fixing that," he muttered, and refused to say more.

In the dojo, Master Splinter was watching his future son in disbelief. He didn't know what surprised him the most: that Leonardo had been going behind his back by consulting the forbidden scrolls or that his son's plan was actually a good one. _Though I should have seen it coming,_ Master Splinter thought with a mixture of sadness and pride. _My sons are obviously taking their own decisions now._

In front of him, Leonardo shifted uncomfortably.

"Sensei? Are you mad at me?"

It was such a childish question to ask that Master Splinter had to repress a smile. _But maybe they still need me._

"No, my son. I am simply… surprised. What I have seen for the past few days is disconcerting, to say the least. It would seem that you and your brothers have been through a lot."

Leonardo smiled.

"You could say that."

The blue-clad turtle watched his father with eyes filled with hope.

"So, do you think it could work?"

Master Splinter nodded solemnly.

"Yes, my son. I think it could work."

A few hours later, the nine mutants were gathered in the dojo. Leonardo's plan was simple. Master Splinter would use a specific mantra to take the younger turtles' memories and pass them to the older turtles. This way, his present sons would forget the recent events and the past wouldn't be disturbed. Leonardo hadn't told his father that he had the power to use the mantras too, so Master Splinter would do it for all of them.

The younger turtles were not very comfortable with it, but they accepted it nonetheless.

"It's a pity we will forget everything," Young Michelangelo sighed. "We had so much fun!"

"There are some memories that I won't mind forgetting," Young Leonardo shrugged.

He still remembered how the older Donatello had humiliated him when the eight turtles had trained together.

Young Raphael exchanged a glance with him and nodded.

"Same here."

"We will remember, guys," Young Donatello clarified. "We will just have to wait a few years for that."

"See you later, then!" The older Michelangelo winked at the younger turtles.

As Master Splinter began to chant, each of his present sons fell asleep while his future sons were standing over them, each paired with his other self.

A few minutes later, the ritual was complete.

The ninja master sighed.

"It is time for me to say goodbye to you."

The future Donatello exchanged a glance with the future Leonardo.

"Sensei," the purple-clad turtle began, "it is important that you forget about these events too. Can you use the mantra on yourself?"

Master Splinter's eyes widened.

"I could, but the ritual wouldn't be complete. I would fall asleep before that."

The four turtles exchanged glances, before Leonardo spoke.

"But if someone else finished it for you, would it still work? Without your older self here, what would happen to the memories?"

"I guess that they would stay hidden," the rat master answered. "Until something triggers them."

He sighed.

"But it is only hypothetical. As I said, I would fall asleep before finishing the mantra."

Master Splinter looked at his sons and tilted his head. They were exchanging knowing glances and Leonardo's fingers were twitching, like they did when the blue-clad turtle was about to say something important. The rat master looked at his son questioningly.

"I think I could finish it for you," Leonardo finally said, not looking at him.

There was shocking surprise in his father's eyes as realization dawned. _He can? Has he really that kind of power and focus, at such a young age?_ He looked at his other sons. Raphael, his hot-tempered son who had learned to fight as a team member with incredible efficiency. Donatello, whose new quiet assurance in both science and ninjitsu would allow them to go back to their time. Michelangelo, whom he had seen fight with unbelievable focus. _And what else have you already done, my sons, that I don't know about?_ Pride filled his heart as he answered.

"In that case, please do it, my son."

A few minutes later, Leonardo let his hands fall at his sides and looked at his sleeping father.

He nodded at his brothers.

"We have to go now. They will wake up soon."

The four turtles regrouped. They spared one last look at their younger selves. Then Donatello activated his device, and the four future turtles were gone.


	15. Epilogue

_Author's Note: And here is the epilogue._

 _Thank you for spending some of your valuable time with my story! If you feel like it, I would appreciate to read your thoughts in the reviews._

 **Epilogue**

Leonardo, Donatello, Michelangelo and Raphael looked at each other.

"Do you think we made it?" Leonardo asked.

At this instant, April entered the dojo.

"Guys, where have you been? You disappeared hours ago! Master Splinter and I were getting worried!"

Donatello grinned. He felt more relaxed than he had been in days.

"I guess we did."

"Nice work, Donnie!" Raphael said before clasping his brother's shoulders affectionately.

"April, you won't believe it! We have been in the past!" Michelangelo exclaimed.

April lifted a brow.

"I _want_ to hear that story."

Later, after the turtles had shared their incredible story with April, Casey and Master Splinter, the ninja master felt buried memories come back to his mind. He closed his eyes to contemplate them.

Casey was overexcited.

"This is unbelievable! You spent almost an entire week in the lair, and your younger selves really had no clue?"

"Yep," Michelangelo said smugly. "We are that good."

"And you even managed to save the world," April added half-proud and half-envious. "I wish I had been there!"

"I don't think it would have been a good idea," Raphael interjected. "Master Splinter was freaking out enough with just the four of us." He remembered too late that said Master Splinter was right here. "Uh, sorry, sensei… I meant…"

"No offense taken, Raphael," the ninja master reassured his son. "I may have been a little overprotective…Nonetheless…"

Master Splinter looked at his blue-clad son. He remembered what had happened now. A phone switched off at the worst possible time, scrolls being tinkered with…

"Leonardo, you have a lot to answer for."

Leonardo gulped.

"And what about prescription? Technically, it happened years ago," he tried.

Master Splinter repressed a smile and shook his head.

"Nice try, my son."

Years ago, four teenage mutant ninja turtles were pleading with their father to allow them to go to the surface.

It was déjà vu for Master Splinter. He didn't want to let them go. They were still so young and vulnerable… And still, something was tugging at a corner of his memory… He couldn't remember what it was, but somehow, deep down, he knew he could let them go. Could let them make the mistakes and learn from it. Somehow, he knew with all his heart that they would be fine.

"You may go…tonight."


End file.
